www/forgejo: Update to 13.0.2

Changelog:

• https://codeberg.org/forgejo/forgejo/src/branch/forgejo/release-notes-published/13.0.2.md

Additional changes:

• Stop setting FORGEJO_WORK_DIR environment variable. It is already hardcoded into the binary, and can be overridden in the configuration file if needed.
• Improve the prestart check.

PR: 287010
PR: 289846
MFH: 2025Q4
Reviewed by: bapt
Differential Revision: https://reviews.freebsd.org/D53394