renovate: Don't update the lockfile

The site is generated with Zola. All our regular Rust dependencies are
essentially dev dependencies, used for testing and the blog post
generator. Updating the lockfile weekly only causes frequent
recompilation for no significant benefit.

Author: senekor

.github/renovate.json5

@@ -2,7 +2,6 @@
     extends: [
         'config:best-practices',
         ':pinAllExceptPeerDependencies',
-        ':maintainLockFilesWeekly',
         ':semanticCommitsDisabled',
         'customManagers:githubActionsVersions',
     ],