External Issue Identifier With Trailing Comma Doesn't Get Linked

[friedrichsenm]

Description

If you have a repo configured to use an external issue tracker and use the alphanumeric issue identifier, then valid issues with a trailing comma won't get dynamically linked in a PR title. For example:
TAG-1234 <PR title text> works
TAG-1234: <PR title text> works
TAG-1234, <PR title text> does NOT work

Gitea Version

1.22.0

Can you reproduce the bug on the Gitea demo site?

No (the demo site is down)

Log Gist

No response

Screenshots

Can't reproduce in demo right now since the site is down

Git Version

No response

Operating System

Ubuntu

How are you running Gitea?

rootless docker image

Database

PostgreSQL