*queueing.errTooManyRequests: too many requests queued

Currently this is being logged to Sentry about 20 million times per week. If we don't care about it we should rescue and ignore it.

https://sentry.gitlap.com/gitlab/gitlab-workhorse-gitlabcom/issues/17013/

*queueing.errTooManyRequests: too many requests queued
  File "/var/cache/omnibus/src/gitlab-workhorse/_build/src/gitlab.com/gitlab-org/gitlab-workhorse/internal/queueing/requests.go", line 31, in func1
  File "/usr/local/go/src/net/http/server.go", line 1422, in ServeHTTP
  File "/var/cache/omnibus/src/gitlab-workhorse/_build/src/gitlab.com/gitlab-org/gitlab-workhorse/internal/upstream/routes.go", line 177, in func1
  File "/usr/local/go/src/net/http/server.go", line 1422, in ServeHTTP
  File "/var/cache/omnibus/src/gitlab-workhorse/_build/src/gitlab.com/gitlab-org/gitlab-workhorse/internal/upstream/upstream.go", line 102, in ServeHTTP
...
(5 additional frame(s) were not displayed)

too many requests queued