Make generated pkg meta more similar to existing

This often avoids making an API call to the server completely, if the
generated XML can be shown to be the same as the existing.

mpcdf_common.py

@@ -415,6 +415,8 @@ def mpcdf_enable_repositories(api_url, project, package, verbose=False, dry_run=
     for enable in build.findall("./enable"):
         build.remove(enable)
 
+    disabled_repos = {disable.get("repository") for disable in build.findall("./disable")}
+
     try:
         enable_repos = get_attribute_values(api_url, project, package, "MPCDF:enable_repositories")
     except Exception:
@@ -443,13 +445,15 @@ def mpcdf_enable_repositories(api_url, project, package, verbose=False, dry_run=
         latest_intel = sorted((c for c in all_compilers if c.startswith("intel")), key=package_sort_key)[-1]
         latest_gcc = sorted((c for c in all_compilers if c.startswith("gcc")), key=package_sort_key)[-1]
 
+    i = len(build)
+
     def enable(name):
-        if name in ignore_repos:
+        if name in ignore_repos or name in disabled_repos:
             return
         node = ElementTree.Element("enable")
         node.set("repository", name)
         node.tail = "\n    "
-        build.insert(0, node)
+        build.insert(i, node)
         if verbose:
             print("Enabling", name)