x/tools/gopls: release version v0.9.5

[findleyr]

This issue tracks progress toward releasing gopls@v0.9.5

• cherry-pick into gopls-release-branch.0.9
• update hard-coded version
• update go.mod/go.sum (remove x/tools replace, update x/tools version)
• tag gopls/v0.9.5-pre.1
• update Github milestone
• write release notes
• smoke test features
• tag gopls/v0.9.5
• update dependencies in master for the next release

[gopherbot]

Change https://go.dev/cl/427904 mentions this issue: gopls: add back x/tools replace directive

[gopherbot]

Change https://go.dev/cl/428596 mentions this issue: [gopls-release-branch.0.9] internal/lsp/cache: clear shouldLoad IDs on load

[gopherbot]

Change https://go.dev/cl/428597 mentions this issue: internal/lsp/debug: update hard-coded version for v0.9.5

[gopherbot]

Change https://go.dev/cl/428598 mentions this issue: gopls: update go.mod for v0.9.5

[gopherbot]

Change https://go.dev/cl/429516 mentions this issue: [gopls-release-branch.0.9] gopls: use golang.org/x/tools@ce397412b6a4