Fix release script to check GH token (#17803)

The current logic didn't work.

changelog.d/17803.misc

@@ -0,0 +1 @@
+Test github token before running release script steps.

scripts-dev/release.py

@@ -40,7 +40,7 @@ import commonmark
 import git
 from click.exceptions import ClickException
 from git import GitCommandError, Repo
-from github import Github
+from github import BadCredentialsException, Github
 from packaging import version
 
 
@@ -323,10 +323,8 @@ def tag(gh_token: Optional[str]) -> None:
 def _tag(gh_token: Optional[str]) -> None:
     """Tags the release and generates a draft GitHub release"""
 
-    if gh_token:
     # Test that the GH Token is valid before continuing.
-        gh = Github(gh_token)
+    check_valid_gh_token(gh_token)
-        gh.get_user()
 
     # Make sure we're in a git repo.
     repo = get_repo_and_check_clean_checkout()
@@ -469,10 +467,8 @@ def upload(gh_token: Optional[str]) -> None:
 def _upload(gh_token: Optional[str]) -> None:
     """Upload release to pypi."""
 
-    if gh_token:
     # Test that the GH Token is valid before continuing.
-        gh = Github(gh_token)
+    check_valid_gh_token(gh_token)
-        gh.get_user()
 
     current_version = get_package_version()
     tag_name = f"v{current_version}"
@@ -569,10 +565,8 @@ def wait_for_actions(gh_token: Optional[str]) -> None:
 
 
 def _wait_for_actions(gh_token: Optional[str]) -> None:
-    if gh_token:
     # Test that the GH Token is valid before continuing.
-        gh = Github(gh_token)
+    check_valid_gh_token(gh_token)
-        gh.get_user()
 
     # Find out the version and tag name.
     current_version = get_package_version()
@@ -806,6 +800,22 @@ def get_repo_and_check_clean_checkout(
     return repo
 
 
+def check_valid_gh_token(gh_token: Optional[str]) -> None:
+    """Check that a github token is valid, if supplied"""
+
+    if not gh_token:
+        # No github token supplied, so nothing to do.
+        return
+
+    try:
+        gh = Github(gh_token)
+
+        # We need to lookup name to trigger a request.
+        _name = gh.get_user().name
+    except BadCredentialsException as e:
+        raise click.ClickException(f"Github credentials are bad: {e}")
+
+
 def find_ref(repo: git.Repo, ref_name: str) -> Optional[git.HEAD]:
     """Find the branch/ref, looking first locally then in the remote."""
     if ref_name in repo.references: