bitbake: tests/fetch: Fix git shallow test failure with git >= 2.48

From git 2.48 release notes:

"""
When "git fetch $remote" notices that refs/remotes/$remote/HEAD is
missing and discovers what branch the other side points with its
HEAD, refs/remotes/$remote/HEAD is updated to point to it.
"""

This means with git 2.48 onwards, there is a mystery "HEAD" revision
appearing in some of our shallow clone tests. We can avoid this by
using the same canonicalization as used for the reference revisions.

This resolves autobuilder failures on the Fedora 40 workers.

(Bitbake rev: c83444d1210740e27b1744d3aa7c5cad4e28db2f)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/tests/fetch.py

@@ -1739,6 +1739,8 @@ class GitShallowTest(FetcherTest):
         if cwd is None:
             cwd = self.gitdir
         actual_refs = self.git(['for-each-ref', '--format=%(refname)'], cwd=cwd).splitlines()
+        # Resolve references into the same format as the comparision (needed by git 2.48 onwards)
+        actual_refs = self.git(['rev-parse', '--symbolic-full-name'] + actual_refs, cwd=cwd).splitlines()
         full_expected = self.git(['rev-parse', '--symbolic-full-name'] + expected_refs, cwd=cwd).splitlines()
         self.assertEqual(sorted(set(full_expected)), sorted(set(actual_refs)))