Migrate config .github/renovate.json (#980)

Co-authored-by: renovate-rancher[bot] <119870437+renovate-rancher[bot]@users.noreply.github.com>

Author: renovate-rancher[bot]

.github/renovate.json

@@ -2,7 +2,7 @@
   "extends": [
     "github>rancher/renovate-config#release"
   ],
-  "baseBranches": [
+  "baseBranchPatterns": [
     "main",
     "release/v0.8",
     "release/v0.7",