remove non-working auto merge

In k8gb-io#1615 auto merge was enabled for [all non-major dependencies](k8gb-io#1052 (comment)). However, the PR cannot be merged without an approving review.
The missing piece would be the following app: https://github.com/apps/renovate-approve. It would approve all PRs created by the renovate bot that have auto merge enabled. Unfortunately, it cannot do it for projects that have CODEOWNERS setup, which is our case:
> Important note: Due to a GitHub limitation, it is not possible to assign any app like this one as a CODEOWNER, so unfortunately this bot won't work that way if you have CODEOWNERS set up.

Since auto merge does not work this PR removes the configuration to avoid any confusion

Signed-off-by: abaguas <[email protected]>

renovate.json5

@@ -27,7 +27,6 @@
       "matchCurrentVersion": "!/^v?0/",
       "groupName": "all non-major dependencies",
       "groupSlug": "all-minor-patch",
-      "automerge": true,
     }, {
         "matchPackageNames": [
         "k8gb-io/k8gb",