ccl/sqlproxyccl: fixes flake on TestDirectoryConnect

[jaylim-crl]

Fixes #76839, #71365.

This commit rewrites the test to use the static directory server instead of the dynamic one. The old one is susceptible to GRPC port reuse and deadlock issues. With this change, only directory_cache_test.go is relying on the dynamic directory server. Once we rewrite that, we can remove the entire test directory implementation.

Release note: None

[cockroach-teamcity]

This change is 

[jaylim-crl]

Added a dummy commit to figure out why make lint in Bazel Essential CI (Cockroach) is failing.

[jaylim-crl]

The make lint failure seems to be an already existing issue: https://cockroachlabs.slack.com/archives/CJ0H8Q97C/p1681997780769209 (unrelated to this PR).

[jeffswenson]

LGTM

[jaylim-crl]

TFTR!

bors r=JeffSwenson

[craig]

Build succeeded:

• Bazel Essential CI (Cockroach)

[jeffswenson]

blathers backport 23.1

[blathers-crl]

Encountered an error creating backports. Some common things that can go wrong:

1. The backport branch might have already existed.
2. There was a merge conflict.
3. The backport branch contained merge commits.

You might need to create your backport manually using the backport tool.

---

error creating merge commit from f45ac17 to blathers/backport-release-23.1-101864: POST https://api.github.com/repos/cockroachdb/cockroach/merges: 409 Merge conflict []

you may need to manually resolve merge conflicts with the backport tool.

Backport to branch 23.1 failed. See errors above.

---

_{🦉 Hoot! I am a Blathers, a bot for CockroachDB. My owner is dev-inf.}