renovate: Preserve semver ranges

This was the intention of the following commit:
f338aa3b8869fc494e2cdd87c6dd8954792e653c

But apparantly the pinning must be explicitly opted-out of.

Author: senekor

.github/renovate.json5

@@ -3,5 +3,6 @@
         'config:best-practices',
         ':semanticCommitsDisabled',
         'customManagers:githubActionsVersions',
+        ":preserveSemverRanges",
     ],
 }