git: Fix git_repository_name.

Without universal_newlines=True or text=True, subprocess.check_output
returns bytes, not str, so it makes no sense to compare its return to
"true".  But upstream Git’s behavior only depends on the filename, not
whether the repository is bare; emulate this more closely.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

Author: andersk

zulip/integrations/git/post-receive

@@ -33,11 +33,10 @@ client = zulip.Client(
 
 
 def git_repository_name() -> str:
-    output = subprocess.check_output(["git", "rev-parse", "--is-bare-repository"])
-    if output.strip() == "true":
-        return os.path.basename(os.getcwd())[: -len(".git")]
-    else:
-        return os.path.basename(os.path.dirname(os.getcwd()))
+    path, name = os.path.split(os.getcwd())
+    if name == ".git":
+        name = os.path.basename(path)
+    return name[: -len(".git")] if name.endswith(".git") else name
 
 
 def git_commit_range(oldrev: str, newrev: str) -> str: