update syntax

Author: parthea

.github/workflows/tests.yaml

@@ -19,6 +19,15 @@ env:
   ALL_PYTHON: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13"]
 
 jobs:
+  all_python_setup:
+    outputs:
+      all_python: ${{ steps.all_python_setup.outputs.all_python }}
+    steps:
+    - name: Set up all python
+      id: all_python
+      run: |
+        all_python=$(echo ${{ vars.ALL_PYTHON }} | jq -Rrc 'split(",")')
+        echo "all_python=$all_python" >> "$GITHUB_OUTPUT"
   docs:
     runs-on: ubuntu-latest
     steps:
@@ -35,11 +44,12 @@ jobs:
       - name: Build the documentation.
         run: nox -s docs
   mypy:
+    needs: all_python_setup
     strategy:
       matrix:
         # Run mypy on all of the supported python versions listed in setup.py
         # https://github.com/python/mypy/blob/master/setup.py
-        python: ${{ fromJSON(ALL_PYTHON) }}
+        python: ${{ fromJSON(needs.all_python_setup.outputs.all_python) }}
         exclude:
           # Remove once https://github.com/googleapis/gapic-generator-python/issues/2303 is fixed
           - python: 3.7
@@ -56,11 +66,12 @@ jobs:
       - name: Check type annotations.
         run: nox -s mypy-${{ matrix.python }}
   showcase:
+    needs: all_python_setup
     strategy:
       # Run showcase tests on the lowest and highest supported runtimes
       matrix:
         # TODO(https://github.com/googleapis/gapic-generator-python/issues/2121) Remove `showcase_w_rest_async` target when async rest is GA.
-        python: ["${{ fromJSON(ALL_PYTHON) }}[0]", "${{ fromJSON(ALL_PYTHON) }}[-1]"]
+        python: ["${{ fromJSON(needs.all_python_setup.outputs.all_python) }}[0]", "${{ fromJSON(needs.all_python_setup.outputs.all_python) }}[-1]"]
         target: [showcase, showcase_w_rest_async]
         logging_scope: ["", "google"]
 
@@ -149,9 +160,10 @@ jobs:
             nox -s ${{ matrix.target }}
   # TODO(yon-mg): add compute unit tests
   showcase-unit:
+    needs: all_python_setup
     strategy:
       matrix:
-        python: ${{ fromJSON(ALL_PYTHON) }}
+        python: ${{ fromJSON(needs.all_python_setup.outputs.all_python) }}
         # TODO(https://github.com/googleapis/gapic-generator-python/issues/2121) Remove `_w_rest_async` variant when async rest is GA.
         variant: ['', _alternative_templates, _mixins, _alternative_templates_mixins, _w_rest_async]
         logging_scope: ["", "google"]