fix: cap CI devbox hostname

[spalladino]

Running ci.sh grind was failing with sethostname: invalid argument. Codex attributed the failure to a long branch name, causing a long instance name, which was too long for sethostname. Confirmed that switching to a shorter branch name fixed the issue.

--- request build instance (SSH) ---
Requesting m6a.48xlarge spot instance (name: spl_fix-web3signer-pipelining-test_amd64_grind-test-cdfb13e6637062de) (type: m6a.48xlarge) (ami: ami-067627aa971a1dcbb) (bid: 8.3136)...
Waiting for instance id for spot request: sir-dvtzjepj...
Timeout waiting for spot request.
Requesting m6a.48xlarge on-demand instance (name: spl_fix-web3signer-pipelining-test_amd64_grind-test-cdfb13e6637062de) (type: m6a.48xlarge) (ami: ami-067627aa971a1dcbb) (bid: 8.3136)...
Instance id: i-0fd2be01d28ec47e5
Waiting for SSH at 13.58.96.227...
--- connect via SSH ---
Stdout is not a tty, running in background...
Host processes pinned to OS CPUs: 88-95,184-191
HOST: fetching EC2 metadata token...
HOST: metadata token acquired.
HOST: decoding credentials...
HOST: starting devbox container...
HOST: devbox container launched (pid=10513). Monitoring for spot termination...
HOST: preparing devbox (uid/gid, docker run)...
docker: Error response from daemon: failed to create task for container: failed to create shim task: OCI runtime create failed: runc create failed: unable to start container process: error during container init: sethostname: invalid argument

[AztecBot]

Flakey Tests

🤖 says: This CI run detected 1 tests that failed, but were tolerated due to a .test_patterns.yml entry.

\033FLAKED\033 (8;;http://ci.aztec-labs.com/c9d85531ede9c852�c9d85531ede9c8528;;�):  yarn-project/end-to-end/scripts/run_test.sh simple src/e2e_epochs/epochs_invalidate_block.parallel.test.ts "archiver skips a descendant of an invalid-attestations checkpoint" (408s) (code: 0) group:e2e-p2p-epoch-flakes