Update dependabot and renovate to target main branch (#14614)

.github/renovate.json5

@@ -1,7 +1,7 @@
 {
   $schema: "https://docs.renovatebot.com/renovate-schema.json",
   labels: ["dependency"],
-  baseBranches: ["next"],
+  baseBranches: ["main"],
   schedule: ["after 01:00 on sunday"],
   postUpdateOptions: ["yarnDedupeHighest"],
   packageRules: [
@@ -18,6 +18,10 @@
       matchPackagePrefixes: ["@typescript-eslint/"],
       groupName: "typescript-eslint",
     },
+    {
+      matchPackagePrefixes: ["@glimmer/"],
+      groupName: "glimmer",
+    },
     {
       branchPrefix: "renovate/website/",
       matchPaths: ["website/package.json"],
@@ -33,4 +37,8 @@
       labels: ["dependency:tools"],
     },
   ],
+  ignoreDeps: [
+    // It's a dependency of `remark-parse`, use same version to reduce size
+    "collapse-white-space",
+  ],
 }