Merge bitcoin/bitcoin#33869: refactor: Avoid -W*-whitespace in git archive

fa95353902 ci: Run macos tasks in a git archive, not git checkout (MarcoFalke)
faf99ae379 refactor: Avoid -W*-whitespace in git archive (MarcoFalke)

Pull request description:

  Otherwise, compilation with GCC-15+ will warn about it:

  ```
  src/clientversion.cpp:33:79: error: trailing whitespace [-Werror=trailing-whitespace=]
     33 | //! git will put "#define GIT_COMMIT_ID ..." on the next line inside archives.
  ```

  Follow-up to https://github.com/bitcoin/bitcoin/pull/32482#issuecomment-3522280482

  Can be tested via `git archive --output=/tmp/a.tar HEAD`

ACKs for top commit:
  fanquake:
    ACK fa95353902

Tree-SHA512: 73940ffc0fd83db557275bd5e993a3c47c5397682a1188447c48e077ead597ba0fc3e5ef9da7b746746ff04a26022ce35ac10768888bbd4707f25b799af43e45

.github/workflows/ci.yml

@@ -138,7 +138,7 @@ jobs:
 
     env:
       DANGER_RUN_CI_ON_HOST: 1
-      BASE_ROOT_DIR: ${{ github.workspace }}
+      BASE_ROOT_DIR: ${{ github.workspace }}/repo_archive
 
     steps:
       - &CHECKOUT
@@ -176,8 +176,16 @@ jobs:
           key: ${{ github.job }}-${{ matrix.job-type }}-ccache-${{ github.run_id }}
           restore-keys: ${{ github.job }}-${{ matrix.job-type }}-ccache-
 
+      - name: Create git archive
+        run: |
+          git log -1
+          git archive --format=tar --prefix=repo_archive/ --output=repo.tar HEAD
+          tar -xf repo.tar
+
       - name: CI script
-        run: ./ci/test_run_all.sh
+        run: |
+          cd repo_archive
+          ./ci/test_run_all.sh
         env:
           FILE_ENV: ${{ matrix.file-env }}