chore: Group renovate build-tools updates (#6201)

These are all released in unison.

Author: MrAlias

renovate.json

@@ -14,6 +14,10 @@
       "matchDepTypes": ["indirect"],
       "enabled": true
     },
+    {
+      "matchPackageNames": ["go.opentelemetry.io/build-tools/**"],
+      "groupName": "build-tools"
+    },
     {
       "matchPackageNames": ["google.golang.org/genproto/googleapis/**"],
       "groupName": "googleapis"