Drop docker.sock mount instructions from build/release workflows

Manually forwarding the host Docker socket into job containers causes
problems for the Gitea runner and isn't needed -- the runner's daemon is
reachable from job containers out of the box.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.gitea/workflows/build.yml

@@ -25,13 +25,10 @@ on:
 jobs:
   build-and-push:
     runs-on: ubuntu-latest
-    # Assumes the runner forwards the host's Docker socket into job
+    # Relies on the Gitea runner's Docker daemon being reachable from job
-    # containers -- if this job fails to reach a daemon, add
+    # containers, which it is out of the box -- no extra runner config needed.
-    #   container.options: -v /var/run/docker.sock:/var/run/docker.sock
-    # (and allow that path in valid_volumes) to the runner's config.yaml.
     container:
       image: docker:cli
-      options: -v /var/run/docker.sock:/var/run/docker.sock
     steps:
       # actions/checkout is a JS action; docker:cli is Alpine-based and has
       # no node on PATH by default (same issue fixed in ci.yml).

.gitea/workflows/release.yml

@@ -24,12 +24,10 @@ on:
 jobs:
   build-and-push:
     runs-on: ubuntu-latest
-    # Assumes the runner forwards the host's Docker socket into job
+    # Relies on the Gitea runner's Docker daemon being reachable from job
-    # containers -- see the matching note in build.yml if this can't reach
+    # containers, which it is out of the box -- no extra runner config needed.
-    # a daemon.
     container:
       image: docker:cli
-      options: -v /var/run/docker.sock:/var/run/docker.sock
     steps:
       # actions/checkout is a JS action; docker:cli is Alpine-based and has
       # no node on PATH by default (same issue fixed in ci.yml).