Add support for searching Go dependencies with `go.mod`

Created by: tsenart

• Implement Go packages integration (ala NPM) with proxy.golang.org
  • https://pkg.go.dev/golang.org/x/[email protected]/zip
  • https://go.dev/ref/mod#goproxy-protocol
  • curl -O https://proxy.golang.org/github.com/oklog/ulid/@v/v1.3.0.zip
• Add go.sum parser to https://sourcegraph.com/github.com/sourcegraph/sourcegraph/-/tree/internal/codeintel/lockfiles
• https://github.com/sourcegraph/sourcegraph/pull/33831 (@stefanhengl).
• https://github.com/sourcegraph/sourcegraph/pull/33180
• Increase default self enforced rate limit values. We're seeing high rate limiting in prod. -> updated from 3000 req/h -> 6000 req/h in external service config (Apri 14, 8.40 UTC)
• [Update DependencySyncScheduler](https://sourcegraph.com/github.com/sourcegraph/sourcegraph/-/blob/enterprise/cmd/worker/internal/codeintel/indexing/dependency_sync_scheduler.go?L23-26&subtree=true
  • Test by opening a PR with a new dependency that doesn't yet exist in production in the lsif_dependency_repos table and verify that it gets inserted after the lsif-go job has ran.
• Fix git.apache.org/thrift.git cloning. It's problematic because it ends in .git https://github.com/sourcegraph/sourcegraph/pull/33942
• Remove NPM only warnings in dependencies search UI and docs
• Update docs: dependencies search and Go modules dependency repos.
• Update CHANGELOG