FIX: Disable pytest caching

The pytest test suite is trying to generate additional
files and it tries to save them to a filesystem that is
for some reason read-only. Since this workflow runs
only in a temporary CI job, the `.pyc` file generation
can be disabled.

Some other fixes are included as well:

1. pydantic<2 not needed anymore
2. Skip the job on forks
3. More readable condition for Anaconda upload
step

.github/workflows/emscripten.yml

@@ -30,8 +30,8 @@ jobs:
   build_wasm_emscripten:
     name: Build PyWavelets for Pyodide
     runs-on: ubuntu-latest
-    # Uncomment the following line to test changes on a fork
-    # if: github.repository == 'PyWavelets/pywt'
+    # Comment out the following line to test changes on a fork
+    if: github.repository == 'PyWavelets/pywt'
     steps:
       - name: Check out repository
         uses: actions/checkout@v4
@@ -44,7 +44,7 @@ jobs:
 
       - name: Install prerequisites
         run: |
-          python -m pip install pyodide-build "pydantic<2"
+          python -m pip install pyodide-build
           echo EMSCRIPTEN_VERSION=$(pyodide config get emscripten_version) >> $GITHUB_ENV
 
       - name: Set up Emscripten toolchain
@@ -70,12 +70,16 @@ jobs:
           pushd demo
           pip install matplotlib pytest
           python -c "import pywt; print(pywt.__version__)"
-          pytest --pyargs pywt -m "not slow"
+          pytest -p no:cacheprovider --pyargs pywt -m "not slow"
 
         # https://anaconda.org/scientific-python-nightly-wheels/pywavelets
         # WARNING: this job will overwrite existing wheels.
       - name: Push to Anaconda PyPI index
-        if: (github.repository == 'PyWavelets/pywt') && (github.event_name == 'push' && github.ref == 'refs/heads/main') || (github.event_name == 'workflow_dispatch' && github.event.inputs.push_wheels == 'true') || (github.event_name == 'schedule')
+        if: >-
+          (github.repository == 'PyWavelets/pywt') &&
+          (github.event_name == 'push' && github.ref == 'refs/heads/main') ||
+          (github.event_name == 'workflow_dispatch' && github.event.inputs.push_wheels == 'true') ||
+          (github.event_name == 'schedule')
         uses: scientific-python/upload-nightly-action@b67d7fcc0396e1128a474d1ab2b48aa94680f9fc # v0.5.0
         with:
           artifacts_path: dist/