Update gitserver image to pull in libcurl fix

[willdollman]

This PR updates the gitserver base image - it downgrades curl to 8.6.0 due to a regression in curl 8.7.0 that affects git fetch. As a side effect, a number of other packages are also upgraded but I don't foresee this being a problem assuming it passes all release tests.

Context from Slack

Image hash taken from https://buildkite.com/sourcegraph/sourcegraph/builds/270158. Updated image url from dockerhub to us.gcr.io as we no longer push to Dockerhub.

Running affected git fetch against broken sourcegraph/gitserver:5.3.9104 image:

Initialized empty Git repository in /data/repos/
error: RPC failed; HTTP 400 curl 22 The requested URL returned error: 400
fatal: unable to write request to remote: Broken pipe

Running against this base image:

Initialized empty Git repository in /data/repos/
remote: Enumerating objects: 2378395, done.
remote: Counting objects: 100% (8632/8632), done.
remote: Compressing objects: 100% (4701/4701), done.
Receiving objects:  25% (594599/2378395), 502.08 MiB | 31.11 MiB/s
[...]

Test plan

• Tested image against problematic git command
• CI