chore(deps): update dependency matplotlib to v3.4.1 (#576)

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This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| [matplotlib](https://matplotlib.org) ([source](https://github.com/matplotlib/matplotlib)) | `==3.3.4` -> `==3.4.1` | [![age](https://badges.renovateapi.com/packages/pypi/matplotlib/3.4.1/age-slim)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://badges.renovateapi.com/packages/pypi/matplotlib/3.4.1/adoption-slim)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://badges.renovateapi.com/packages/pypi/matplotlib/3.4.1/compatibility-slim/3.3.4)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://badges.renovateapi.com/packages/pypi/matplotlib/3.4.1/confidence-slim/3.3.4)](https://docs.renovatebot.com/merge-confidence/) |

---

### Release Notes

<details>
<summary>matplotlib/matplotlib</summary>

### [`v3.4.1`](https://github.com/matplotlib/matplotlib/releases/v3.4.1)

[Compare Source](https://github.com/matplotlib/matplotlib/compare/v3.4.0...v3.4.1)

This is the first bugfix release of the 3.4.x series.

This release contains several critical bug-fixes:

-   fix errorbar when specifying fillstyle
-   fix Inkscape cleanup at exit on Windows for tests
-   fix legends of colour-mapped scatter plots
-   fix positioning of annotation fancy arrows
-   fix size and color rendering for 3D scatter plots
-   fix suptitle manual positioning when using constrained layout
-   respect antialiasing settings in cairo backends as well

### [`v3.4.0`](https://github.com/matplotlib/matplotlib/releases/v3.4.0)

[Compare Source](https://github.com/matplotlib/matplotlib/compare/v3.3.4...v3.4.0)

Highlights of this release include:

-   Figure and Axes creation / management
    -   New subfigure functionality
    -   Single-line string notation for `subplot_mosaic`
    -   Changes to behavior of Axes creation methods (`gca`, `add_axes`, `add_subplot`)
    -   `add_subplot`/`add_axes` gained an _axes_class_ parameter
    -   Subplot and subplot2grid can now work with constrained layout
-   Plotting methods
    -   `axline` supports transform parameter
    -   New automatic labeling for bar charts
    -   A list of hatches can be specified to `bar` and `barh`
    -   Setting `BarContainer` orientation
    -   Contour plots now default to using `ScalarFormatter`
    -   `Axes.errorbar` cycles non-color properties correctly
    -   `errorbar` _errorevery_ parameter matches _markevery_
    -   `hexbin` supports data reference for _C_ parameter
    -   Support callable for formatting of Sankey labels
    -   `Axes.spines` access shortcuts
    -   New `stairs` method and `StepPatch` artist
    -   Added _orientation_ parameter for stem plots
    -   Angles on Bracket arrow styles
    -   `TickedStroke` patheffect
-   Colors and colormaps
    -   Collection color specification and mapping
    -   Transparency (alpha) can be set as an array in collections
    -   pcolormesh has improved transparency handling by enabling snapping
    -   IPython representations for Colormap objects
    -   `Colormap.set_extremes` and `Colormap.with_extremes`
    -   Get under/over/bad colors of Colormap objects
    -   New `cm.unregister_cmap` function
    -   New `CenteredNorm` for symmetrical data around a center
    -   New `FuncNorm` for arbitrary normalizations
    -   GridSpec-based colorbars can now be positioned above or to the left of the main axes
-   Titles, ticks, and labels
    -   supxlabel and supylabel
    -   Shared-axes `subplots` tick label visibility is now correct for top or left labels
    -   An iterable object with labels can be passed to `Axes.plot`
-   Fonts and Text
    -   Text transform can rotate text direction
    -   `matplotlib.mathtext` now supports _overset_ and _underset_ LaTeX symbols
    -   _math_fontfamily_ parameter to change `Text` font family
    -   `TextArea`/`AnchoredText` support _horizontalalignment_
    -   PDF supports URLs on Text artists
-   rcParams improvements
    -   New rcParams for dates: set converter and whether to use interval_multiples
    -   Date formatters now respect _usetex_ rcParam
    -   Setting _image.cmap_ to a Colormap
    -   Tick and tick label colors can be set independently using rcParams
-   3D Axes improvements
    -   Errorbar method in 3D Axes
    -   Stem plots in 3D Axes
    -   3D Collection properties are now modifiable
    -   Panning in 3D Axes
-   Interactive tool improvements
    -   New `RangeSlider` widget
    -   Sliders can now snap to arbitrary values
    -   Pausing and Resuming Animations
-   Sphinx extensions
    -   `plot_directive` _caption_ option
-   Backend-specific improvements
    -   Consecutive rasterized draws now merged
    -   Support raw/rgba frame format in `FFMpegFileWriter`
    -   nbAgg/WebAgg support middle-click and double-click
    -   nbAgg support binary communication
    -   Indexed color for PNG images in PDF files when possible
    -   Improved font subsettings in PDF/PS
    -   Kerning added to strings in PDFs
    -   Fully-fractional HiDPI in QtAgg
    -   wxAgg supports fullscreen toggle

</details>

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samples/snippets/requirements.txt

@@ -4,7 +4,8 @@ google-auth-oauthlib==0.4.4
 grpcio==1.36.1
 ipython==7.16.1; python_version < '3.7'
 ipython==7.17.0; python_version >= '3.7'
-matplotlib==3.3.4
+matplotlib==3.3.4; python_version < '3.7'
+matplotlib==3.4.1; python_version >= '3.7'
 pandas==1.1.5; python_version < '3.7'
 pandas==1.2.0; python_version >= '3.7'
 pyarrow==3.0.0