CI: remove tmate used for debugging

Also remove dead code selecting pip version

.github/actions/install-sphinx/action.yml

@@ -9,8 +9,7 @@ runs:
     - shell: bash
       run: |
         set -x
-        pip=$(command -v pip pip3 | head -1)
-        sudo "$pip" install uv --break-system-packages
+        sudo pip install uv --break-system-packages
         # Check that pyproject.toml and the lock file are in sync.
         # TODO Use "uv" to install Python as well.
         : 'Note that --no-managed-python below would be implied but be explicit'

.github/workflows/test.yml

@@ -148,9 +148,6 @@ jobs:
     - name: make fish_run_tests
       run: |
         make -C build VERBOSE=1 fish_run_tests
-    - name: Setup tmate session
-      if: ${{ failure() }}
-      uses: mxschmitt/action-tmate@v3
 
   windows:
     runs-on: windows-latest