Remove bazel version hack

The upstream patch has landed, so we don't need this anymore.

Change-Id: I08a6705f189b2a24b737ab4f52bb7f449879fdf1

playbooks/zuul/gerrit/repos.yaml

@@ -53,9 +53,3 @@
       command: "mv docker/gerrit/bazel/build-gerrit.sh /home/zuul/src/gerrit.googlesource.com/gerrit"
       args:
         chdir: /home/zuul/src/opendev.org/opendev/system-config
-
-    # TODO(mordred) Remove this line when
-    # https://gerrit-review.googlesource.com/c/gerrit/+/237495
-    # lands.
-    - name: Overwrite bazel version
-      shell: "echo 0.29.1 > /home/zuul/src/gerrit.googlesource.com/gerrit/.bazelversion"