Add issue dependencies documentation to gitea skill

Documents the new tea CLI dependency management commands:
- tea issues deps list - list blockers
- tea issues deps add - add dependency (same or cross-repo)
- tea issues deps remove - remove dependency

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

skills/gitea/SKILL.md

@@ -70,6 +70,13 @@ tea issues reopen <number>
 
 # Labels
 tea issues edit <number> --labels "bug,help wanted"
+
+# Dependencies
+tea issues deps list <number>              # List blockers for an issue
+tea issues deps add <issue> <blocker>      # Add dependency (issue is blocked by blocker)
+tea issues deps add 5 3                    # Issue #5 depends on #3
+tea issues deps add 5 owner/repo#3         # Cross-repo dependency
+tea issues deps remove <issue> <blocker>   # Remove a dependency
 ```
 
 ### Pull Requests