build: Fix Ubuntu distro for clang-format-20 (#240)

Author: jidicula

.github/workflows/clang-format-image.yml

@@ -31,8 +31,8 @@ jobs:
       fail-fast: false
       matrix:
         version-pair:
-          - {version: "20", ubuntu: "oracular"}
-          - {version: "19", ubuntu: "oracular"}
+          - {version: "20", ubuntu: "plucky"}
+          - {version: "19", ubuntu: "plucky"}
           - {version: "18", ubuntu: "noble"}
           - {version: "17", ubuntu: "noble"}
           - {version: "16", ubuntu: "noble"}