ci: drop flint renovate follow-up

Signed-off-by: Gregor Zeitlinger <gregor.zeitlinger@grafana.com>

Author: zeitlinger

.github/renovate.json5

@@ -1,7 +1,6 @@
 {
   $schema: 'https://docs.renovatebot.com/renovate-schema.json',
   extends: [
-    "github>grafana/flint#v0.21.0",
     'config:best-practices',
     'helpers:pinGitHubActionDigestsToSemver',
   ],
@@ -145,6 +144,17 @@
     },
   ],
   customManagers: [
+    {
+      // keep SHA-pinned raw.githubusercontent.com URLs in mise.toml up to date
+      customType: 'regex',
+      datasourceTemplate: 'github-tags',
+      managerFilePatterns: [
+        '/^mise\\.toml$/',
+      ],
+      matchStrings: [
+        'https://raw\\.githubusercontent\\.com/(?<depName>[^/]+/[^/]+)/(?<currentDigest>[a-f0-9]{40})/.*#\\s*(?<currentValue>v\\S+)',
+      ],
+    },
     {
       customType: 'regex',
       datasourceTemplate: 'java-version',