Remove tests locking down our support of no python installation.

While it would be nice to not require all toolchains to exist to build our repo, this isn't compatible with the new rules_python setup.  Long-term, we may split up our bazel repository per-language to solve this problem in a different way.

PiperOrigin-RevId: 811440399
diff --git a/.github/workflows/test_upb.yml b/.github/workflows/test_upb.yml
index 56588ed..187af00 100644
--- a/.github/workflows/test_upb.yml
+++ b/.github/workflows/test_upb.yml
@@ -123,28 +123,6 @@
           bazel: ${{ matrix.config.bazel-command }} ${{ matrix.config.flags }} //bazel/... //benchmarks/... //lua/... //python/... //upb/... //upb_generator/...
           version: 7.6.1
 
-  no-python:
-    strategy:
-      fail-fast: false   # Don't cancel all jobs if one fails.
-    name: No System Python
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout pending changes
-        uses: protocolbuffers/protobuf-ci/checkout@v4
-        with:
-          ref: ${{ inputs.safe-checkout }}
-      - name: Run tests
-        uses: protocolbuffers/protobuf-ci/bazel-docker@v4
-        with:
-          image: us-docker.pkg.dev/protobuf-build/containers/common/linux/bazel:7.6.1-e0df73e51131ccaf53451355d22577f377357604
-          credentials: ${{ secrets.GAR_SERVICE_ACCOUNT }}
-          bazel-cache: "upb-bazel-no-python"
-          bash: >-
-            which python3 &&
-            mv `which python3` /tmp &&
-            ! which python3 &&
-            bazel test $BAZEL_FLAGS --noenable_bzlmod //python/... -- -//python/dist:source_wheel -//python:aarch64_test -//python:x86_64_test -//python:google/protobuf/pyext/_message.so -//python:proto_api
-
   build_wheels:
     name: Build Wheels
     runs-on: ubuntu-latest