Disable caching for pushes to main branch and consolidate caching logic (pyvista#7187)

Author: user27182

.github/workflows/docs.yml

@@ -21,7 +21,16 @@ concurrency:
   cancel-in-progress: true
 
 env:
-  USE_CACHE: ${{ (github.event_name == 'workflow_dispatch' && github.event.inputs.cache == 'true') || (github.event_name == 'pull_request') || (github.event_name == 'push') }}
+  USE_CACHE: ${{
+    (
+    (github.event_name == 'workflow_dispatch' && github.event.inputs.cache == 'true') ||
+    (github.event_name == 'pull_request') ||
+    (github.event_name == 'push')
+    ) &&
+    !startsWith(github.ref, 'refs/tags/v') &&
+    !startsWith(github.ref, 'refs/heads/release/') &&
+    !startsWith(github.ref, 'refs/heads/main')
+    }}
   PYDEVD_DISABLE_FILE_VALIDATION: "1"
   PYTEST_ADDOPTS: "--color=yes"
   FORCE_COLOR: "True"
@@ -66,21 +75,21 @@ jobs:
 
       - name: Cache Sphinx-Gallery Examples
         uses: actions/cache@v4
-        if: env.USE_CACHE == 'true' && !startsWith(github.ref, 'refs/heads/release/') && !startsWith(github.ref, 'refs/tags/v') && (! github.event_name == 'pull_request' || ! contains(github.event.pull_request.labels.*.name, 'no-gallery-cache'))
+        if: env.USE_CACHE == 'true' && (! github.event_name == 'pull_request' || ! contains(github.event.pull_request.labels.*.name, 'no-gallery-cache'))
         with:
           path: doc/source/examples/
           key: doc-examples-${{ hashFiles('pyvista/_version.py') }}
 
       - name: Cache example data
         uses: actions/cache@v4
-        if: env.USE_CACHE == 'true' && !startsWith(github.ref, 'refs/heads/release/') && !startsWith(github.ref, 'refs/tags/v')  && (! github.event_name == 'pull_request' || ! contains(github.event.pull_request.labels.*.name, 'no-example-data-cache'))
+        if: env.USE_CACHE == 'true' && (! github.event_name == 'pull_request' || ! contains(github.event.pull_request.labels.*.name, 'no-example-data-cache'))
         with:
           path: ${{ env.PYVISTA_EXAMPLE_DATA_PATH }}
           key: example-data-1-${{ hashFiles('pyvista/_version.py') }}
 
       - name: Cache Sphinx build directory
         uses: actions/cache@v4
-        if: env.USE_CACHE == 'true' && !startsWith(github.ref, 'refs/heads/release/') && !startsWith(github.ref, 'refs/tags/v')  && (! github.event_name == 'pull_request' || ! contains(github.event.pull_request.labels.*.name, 'no-sphinx-build-cache'))
+        if: env.USE_CACHE == 'true' && (! github.event_name == 'pull_request' || ! contains(github.event.pull_request.labels.*.name, 'no-sphinx-build-cache'))
         with:
           path: doc/_build/
           key: doc-examples-${{ hashFiles('pyvista/_version.py') }}