Bump agent skills to v0.1.2 (#4687)

## Summary
- Bump `defaultSkillsRepoRef` from `v0.1.1` to `v0.1.2` in the agent
skills installer.

## Test plan
- [ ] Verify skills installation pulls from the correct tag.

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

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: arsenyinfo

experimental/aitools/lib/installer/installer.go

@@ -21,7 +21,7 @@ const (
 	skillsRepoOwner      = "databricks"
 	skillsRepoName       = "databricks-agent-skills"
 	skillsRepoPath       = "skills"
-	defaultSkillsRepoRef = "v0.1.1"
+	defaultSkillsRepoRef = "v0.1.2"
 )
 
 func getSkillsRef() string {