gopls/v0.12.1

This release fixes a few regressions/crashes in the v0.12.0 release:

• Unimported completion should use fuzzy matching (golang/go#60545).
• Fix a crash when method has receiver type comparable (golang/go#60544).
• Fix for documentHighlight on import paths (golang/go#60435 -- this was pre-existing).
• Clear vulncheck diagnostics when they are toggled off (golang/go#60574).

These are also summarized in the release milestone.