Don't run the PyPi job all the time

.github/workflows/pypi.yml

@@ -3,7 +3,6 @@ on:
   push:
     branches:
       - main
-      - auto-release
   pull_request:
     branches: [main]
   release:
@@ -16,10 +15,49 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.event_name == 'pull_request' && github.head_ref || github.sha }}
   cancel-in-progress: true
 
+permissions: {}
+
 jobs:
+  check_changes:
+    runs-on: ubuntu-latest
+    outputs:
+      should_run: ${{ steps.set_should_run.outputs.should_run }}
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+      - uses: dorny/paths-filter@de90cc6fb38fc0963ad72b210f1f284cd68cea36  # v3.0.2
+        id: filter
+        with:
+          filters: |
+            any_changed:
+              - '.github/workflows/pypi.yml'
+              - 'pyproject.toml'
+              - 'setup.py'
+              - 'pytensor/_version.py'
+              - 'pytensor/scan_perform.pyx'
+              - 'pytensor/scan_perform_ext.py'
+      - name: Set should_run output
+        id: set_should_run
+        run: |
+          if [[ "${{ github.event_name == 'release' || 
+                (
+                  github.ref == 'refs/heads/main' || 
+                  github.event_name == 'pull_request' 
+                ) && steps.filter.outputs.any_changed == 'true' 
+              }}" == "true" ]]; then
+            echo "should_run=true" >> $GITHUB_OUTPUT
+          else
+            echo "should_run=false" >> $GITHUB_OUTPUT
+          fi
+
   # The job to build precompiled pypi wheels.
   make_sdist:
     name: Make SDist
+    needs: check_changes
+    # Run if it's a release or if relevant files changed on main
+    if: |
+      needs.check_changes.outputs.should_run == 'true'
     runs-on: ubuntu-latest
     permissions:
       # write id-token and attestations are required to attest build provenance
@@ -49,6 +87,10 @@ jobs:
 
   run_checks:
     name: Build & inspect our package.
+    needs: check_changes
+    # Run if it's a release or if relevant files changed on main
+    if: |
+      needs.check_changes.outputs.should_run == 'true'
     # Note: the resulting builds are not actually published.
     # This is purely for additional testing and diagnostic purposes.
     runs-on: ubuntu-latest
@@ -62,6 +104,10 @@ jobs:
 
   build_wheels:
     name: Build wheels for ${{ matrix.platform }}
+    needs: check_changes
+    # Run if it's a release or if relevant files changed on main
+    if: |
+      needs.check_changes.outputs.should_run == 'true'
     runs-on: ${{ matrix.platform }}
     permissions:
       # write id-token and attestations are required to attest build provenance
@@ -96,6 +142,10 @@ jobs:
 
   build_universal_wheel:
     name: Build universal wheel for Pyodide
+    needs: check_changes
+    # Run if it's a release or if relevant files changed on main
+    if: |
+      needs.check_changes.outputs.should_run == 'true'
     runs-on: ubuntu-latest
     permissions:
       # write id-token and attestations are required to attest build provenance
@@ -133,7 +183,7 @@ jobs:
 
   check_dist:
     name: Check dist
-    needs: [make_sdist,build_wheels]
+    needs: [check_changes, make_sdist, build_wheels]
     runs-on: ubuntu-22.04
     steps:
       - uses: actions/download-artifact@v4