Trigger OCI builds only on code changes

Prior to this change, we built the OCI for almost any change. That
doesn't make sense. For example, when there were changes to CI, it
didn't make because RabbitMQ had not changed.

CI will now build dev OCI images when there are actual code changes, or
changes to rabbit dependencies.

.github/workflows/oci-make.yaml

@@ -6,12 +6,12 @@
 name: OCI (make)
 on:
   push:
-    paths-ignore:
+    paths:
-      - '.github/workflows/secondary-umbrella.yaml'
+      - deps/**
-      - '.github/workflows/update-elixir-patches.yaml'
+      - scripts/**
-      - '.github/workflows/update-otp-patches.yaml'
+      - Makefile
-      - '.github/workflows/release-alphas.yaml'
+      - plugins.mk
-      - '*.md'
+      - rabbitmq-components.mk
   workflow_dispatch:
     inputs:
       otp_version: