Release v0.42.1

[h9jiang]

Release note
https://github.com/golang/vscode-go/releases/tag/v0.42.1

[gopherbot]

Change https://go.dev/cl/611835 mentions this issue: extension/CHANGELOG.md: prepare for v0.42.1

[gopherbot]

Change https://go.dev/cl/612039 mentions this issue: [release-v0.42] extension/CHANGELOG.md: prepare for v0.42.1

[gopherbot]

Change https://go.dev/cl/612040 mentions this issue: [release-v0.42] extension/package.json: prepare for v0.42.1