apacheGH-41735: [CI][Archery] Update archery to be compatible with pygit2 1.15 API change (apache#41739)

### Rationale for this change

pygit2 updated how they expose some of the `GIT_OBJ` variables to use `GIT_OBJECT` prefix here: libgit2/pygit2@8b3861b

### What changes are included in this PR?

Update code to make it compatible with both possible APIs.

### Are these changes tested?

Via archery

### Are there any user-facing changes?

No
* GitHub Issue: apache#41735

Authored-by: Raúl Cumplido <raulcumplido@gmail.com>
Signed-off-by: Sutou Kouhei <kou@clear-code.com>

Author: raulcd

dev/archery/archery/crossbow/core.py

@@ -427,8 +427,14 @@ def create_branch(self, branch_name, files, parents=None, message='',
         return branch
 
     def create_tag(self, tag_name, commit_id, message=''):
+        git_object_commit = (
+            pygit2.GIT_OBJECT_COMMIT
+            if getattr(pygit2, 'GIT_OBJECT_COMMIT')
+            else pygit2.GIT_OBJ_COMMIT
+        )
         tag_id = self.repo.create_tag(tag_name, commit_id,
-                                      pygit2.GIT_OBJ_COMMIT, self.signature,
+                                      git_object_commit,
+                                      self.signature,
                                       message)
 
         # append to the pushable references