Skip sdist providers installation for non-canary builds (#26671)

The sdist providers installation takes a long time and it is unlikely
to fail if wheel installation succeeds. We should skip running the
providers builds for PRs to speed them up. In case there will be
any problem with sdist installation, we will catch it in our
"canary" builds anyway.

.github/workflows/ci.yml

@@ -899,7 +899,10 @@ ${{ hashFiles('.pre-commit-config.yaml') }}"
     env:
       RUNS_ON: ${{ needs.build-info.outputs.runs-on }}
       PYTHON_MAJOR_MINOR_VERSION: ${{ needs.build-info.outputs.default-python-version }}
-    if: needs.build-info.outputs.image-build == 'true' && needs.build-info.outputs.default-branch == 'main'
+    if: >
+      needs.build-info.outputs.image-build == 'true' &&
+      needs.build-info.outputs.default-branch == 'main' &&
+      needs.build-info.outputs.canary-run == 'true'
     steps:
       - name: Cleanup repo
         run: docker run -v "${GITHUB_WORKSPACE}:/workspace" -u 0:0 bash -c "rm -rf /workspace/*"