fix: also install bec_server on branch in CI

.gitlab-ci.yml

@@ -60,6 +60,7 @@ stages:
 .install-repos: &install-repos
   - pip install -e ./ophyd_devices
   - pip install -e ./bec/bec_lib[dev]
+  - pip install -e ./bec/bec_server[dev]
   - pip install -e ./bec/bec_ipython_client
   - pip install -e ./bec/pytest_bec_e2e