fix: add a retry for mise installs

Retry mise install when it fails, as a workaround for parallel
installation.

asdf-tool-versions.yml

@@ -72,7 +72,20 @@ validate_mise_tool_versions:
       ssh-keyscan gitlab.com >> ~/.ssh/known_hosts;
       ssh -T git@gitlab.com || true;
       fi
-    - ./scripts/install-asdf-plugins.sh
+    # mise installs plugins in parallel, so order may lead to breaks when some plugins require others
+    # the best workaround is to use `.mise.toml` with dependencies, but we can't do this until the
+    # migration off asdf, in https://gitlab.com/gitlab-com/runbooks/-/issues/134 is complete.
+    # until then, a retry should be sufficient.
+    - >
+      ./scripts/install-asdf-plugins.sh || {
+        echo "mise install failed, trying again without parallel jobs..."
+
+        # Use shims so that plugins can find dependencies
+        eval $(mise env --shell bash)
+
+        # Skip parallel installs for the retry
+        MISE_JOBS=1 ./scripts/install-asdf-plugins.sh
+      }
     - ./scripts/update-asdf-version-variables.sh
     - git diff --exit-code
   after_script: |