ci: always use python 3.9 for building schemas (#5722)

.github/workflows/python-CI.yml

@@ -159,9 +159,8 @@ jobs:
     needs: changes
     if: ${{ needs.changes.outputs.phoenix == 'true' }}
     strategy:
-      fail-fast: false
       matrix:
-        py: [3.12, 3.13]
+        py: [3.9]
         os: [ubuntu-latest]
     runs-on: ${{ matrix.os }}
     steps:
@@ -189,12 +188,9 @@ jobs:
     needs: changes
     if: ${{ needs.changes.outputs.phoenix == 'true' }}
     strategy:
-      fail-fast: false
       matrix:
-        py: [3.12, 3.13]
+        py: [3.9]
         os: [ubuntu-latest]
-        exclude:
-          - py: 3.13
     runs-on: ${{ matrix.os }}
     steps:
       - name: Checkout repository
@@ -221,8 +217,7 @@ jobs:
     if: ${{ needs.changes.outputs.proto == 'true' }}
     strategy:
       matrix:
-        # uv fails on 3.12 as of 10/16/2024 when installing protobuf dependencies
-        py: [3.11]
+        py: [3.9]
         os: [ubuntu-latest]
     runs-on: ${{ matrix.os }}
     steps:

tox.ini

@@ -104,7 +104,8 @@ commands =
   jupyter nbconvert --ClearOutputPreprocessor.enabled=True --ClearMetadataPreprocessor.enabled=True --inplace {posargs}
 
 [testenv:build_graphql_schema]
-description = Export GraphQL schema to a file
+description = Export GraphQL schema to a file (Python 3.9)
+basepython = python3.9
 changedir = app
 deps =
   -r requirements/build-graphql-schema.txt
@@ -115,7 +116,8 @@ commands =
   strawberry export-schema phoenix.server.api.schema:_EXPORTED_GRAPHQL_SCHEMA -o schema.graphql
 
 [testenv:build_openapi_schema]
-description = Export OpenAPI schema to a file
+description = Export OpenAPI schema to a file (Python 3.9)
+basepython = python3.9
 changedir = schemas
 commands_pre =
   uv pip install --strict --reinstall-package arize-phoenix ../.
@@ -124,7 +126,8 @@ commands =
   python -m phoenix.server.api.openapi.main -o openapi.json
 
 [testenv:compile_protobuf]
-description = Compile protobuf files
+description = Compile protobuf files (Python 3.9)
+basepython = python3.9
 deps =
   -r requirements/compile-protobuf.txt
 commands =