x/tools/gopls: reenable tests suppressed due to lack of build{ssa,ir} support for range-over-func or gotypesalias=1

[adonovan]

A number of gopls tests have been skipped. We shouldn't forget to reenable them when the upstream issues are fixed.

Pending CL adding SSA support for range-over-func:

• https://go.dev/cl/555075

Upstream issues:

• Support GOEXPERIMENT=rangefunc dominikh/go-tools#1494
• audit staticcheck for GODEBUG=gotypesalias=1 support dominikh/go-tools#1523

[gopherbot]

Change https://go.dev/cl/584395 mentions this issue: gopls/internal/test/integration/misc: disable staticcheck test

[gopherbot]

Change https://go.dev/cl/584298 mentions this issue: gopls/internal/test/integration/misc: disable another staticcheck test

[adonovan]

Current status:

• https://go.dev/cl/586076/ updates gopls' staticcheck, but cannot be merged until either staticcheck downgrades its go.mod back to go1.19, or downgrades to go1.21 AND the go1.23 release occurs AND gopls 16 is released (due to x/tools/gopls: once Go 1.23 is released, require Go 1.21+ (forward compatibility) to build gopls #65917).
• https://go.dev/cl/589275 reverts the workaround that disables staticcheck buildir on packages that use iter, which is now ~all packages. This cannot be merged until the parent is merged.

[gopherbot]

Change https://go.dev/cl/623295 mentions this issue: Revert "gopls/internal/analysis: disable ssa/ir analyzers on range-over-func"