Add submodules: recursive temporarily, for testing

Add `submodules: recursive` to the `actions/checkout` step in every
workflow that runs the test suite (`cygwin-test.yml`,
`pythonpackage.yml`, `alpine-test.yml`). This is *temporary* and will be
reverted after the bugfix, with the explicit intent of demonstrating
that the bugfix works regardless of which mechanism populates the
submodules.

The standing decision is to NOT use `submodules: recursive` in CI.
`init-tests-after-clone.sh` is the documented setup mechanism that
downstream packagers (Arch Linux and others) rely on, and keeping it as
the sole submodule source on upstream CI is meant to catch regressions
like #1713 before they reach distros. See #1715 for the full rationale.

The CI run on this commit is expected to show:

- Cygwin (`test-cygwin`): the `safe.directory` bug still triggers, with
  the same `ValueError`/`IndexError`/`AssertionError` pattern as the
  previous commits. The bug is independent of which process clones the
  submodules; the gitdb worktree directory itself is created Admin-owned
  by the outer `git clone`'s checkout phase before any submodule init
  runs, regardless of which mechanism populates the submodule contents
  afterward.

- Linux / macOS / native Windows (`Python package`) and Alpine Linux
  (`test-alpine`): tests pass as before. These platforms are unaffected
  by the bug.

Each workflow's checkout step carries an inline comment pointing
at #1715 so the temporary nature of the change is legible at a glance.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: EliahKagan

.github/workflows/alpine-test.yml

@@ -29,6 +29,9 @@ jobs:
     - uses: actions/checkout@v6
       with:
         fetch-depth: 0
+        # Temporary, for testing. The standing decision is to NOT pre-clone
+        # submodules on CI; see https://github.com/gitpython-developers/GitPython/pull/1715
+        submodules: recursive
 
     - name: Set workspace ownership
       run: |

.github/workflows/cygwin-test.yml

@@ -39,6 +39,9 @@ jobs:
       uses: actions/checkout@v6
       with:
         fetch-depth: 0
+        # Temporary, for testing. The standing decision is to NOT pre-clone
+        # submodules on CI; see https://github.com/gitpython-developers/GitPython/pull/1715
+        submodules: recursive
 
     - &install-cygwin
       name: Install Cygwin

.github/workflows/pythonpackage.yml

@@ -53,6 +53,9 @@ jobs:
     - uses: actions/checkout@v6
       with:
         fetch-depth: 0
+        # Temporary, for testing. The standing decision is to NOT pre-clone
+        # submodules on CI; see https://github.com/gitpython-developers/GitPython/pull/1715
+        submodules: recursive
 
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v6