CI: Add raw build and import step (should fail) (#543)

* CI: Add raw build and import step
* fix: Guard ConstrainedSR3 imports

I'm not sure where this happened, but since ConstrainedSR3 needs
CVXPY (an optional dependency), imports of it need to be guarded
depending on whether user has cvxpy installed.

Also, since PEP 690 was rejected, removed those comments

Also
* Fix example 8 notebook headers to pass build
* Make doc build more verbose

.github/workflows/main.yml

@@ -8,27 +8,48 @@ on:
     branches:
       - master
 
+
 jobs:
-  Linting:
+  linting:
+    name: Linting
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Python
-        uses: actions/setup-python@v3
+        uses: actions/setup-python@v4
         with:
           python-version: "3.9"
       - name: Linting
         run: |
           pip install pre-commit
           pre-commit run --all-files
 
-  Docs:
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up Python
+      uses: actions/setup-python@v4
+      with:
+        python-version: "3.9"
+    - name: build
+      run: pip install .
+    - name: test import
+      run: python -c "import pysindy"
+
+  docs:
+    name: Docs
     runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: "Set up Python"
-      uses: actions/setup-python@v3
+      uses: actions/setup-python@v4
       with:
           python-version: "3.10"
     - name: Install doc dependencies
@@ -42,18 +63,20 @@ jobs:
         cd docs
         python -m sphinx -T -E -W -b html -d _build/doctrees . _build/html
 
-  Tests:
-    needs: Linting
+  tests:
+    name: Tests
+    needs: linting
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
       max-parallel: 4
       matrix:
         python-version: ["3.9", "3.11"]
+
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v3
+      uses: actions/setup-python@v4
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install dependencies

docs/conf.py

@@ -125,7 +125,7 @@ def setup(app):
             new_dir = doc_examples / notebook.parent.stem
         new_dir.mkdir(exist_ok=True)
         new_file = new_dir / "example.ipynb"
-        print(f"Creating file {new_file}")
+        print(f"Copying {notebook} to {new_file}")
         shutil.copy(notebook, new_file)
     # Notebook 15 uses an image file
     (doc_examples / "15_pysindy_lectures/data").mkdir(exist_ok=True)