guard 3rd party package installation path

[lxning]

Description

Please read our CONTRIBUTING.md prior to creating your first pull request.

Please include a summary of the feature or issue being fixed. Please also include relevant motivation and context. List any dependencies that are required for this change.

Make sure

• the process of pip installation runs under tmp dir
• the 3rd party package is installed under tmp dir

Fixes #(issue)
#2664

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

Feature/Issue validation/testing

Please describe the Unit or Integration tests that you ran to verify your changes and relevant result summary. Provide instructions so it can be reproduced.
Please also list any relevant details for your test configuration.

• Test A
  Logs for Test A

• Test B
  Logs for Test B

Checklist:

• Did you have fun?
• Have you added tests that prove your fix is effective or that this feature works?
• Has code been commented, particularly in hard-to-understand areas?
• Have you made corresponding changes to the documentation?

[codecov]

Codecov Report

Merging #2687 (851c2d2) into master (726dad2) will not change coverage.
Report is 1 commits behind head on master.
The diff coverage is n/a.

❗ Current head 851c2d2 differs from pull request most recent head eae1ff8. Consider uploading reports for the commit eae1ff8 to get more accurate results

@@           Coverage Diff           @@
##           master    #2687   +/-   ##
=======================================
  Coverage   72.39%   72.39%           
=======================================
  Files          85       85           
  Lines        3956     3956           
  Branches       58       58           
=======================================
  Hits         2864     2864           
  Misses       1088     1088           
  Partials        4        4           

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[msaroufim]

In case it's too annoying to keep retriggering the workflow feel free to run it on pushes here https://github.com/pytorch/serve/blob/master/.github/workflows/codeql.yml#L15

I didn't realize github code scanning would nicely render things as comments feels like a good behavior to have by default on