Use ubuntu-slim runners

Author: josh

.github/workflows/merge.yml

@@ -8,7 +8,7 @@ permissions:
 
 jobs:
   merge:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-slim
     if: github.actor == 'dependabot[bot]' && github.repository == 'josh/lazy-nvim-nix'
 
     steps:

.github/workflows/nix.yml

@@ -13,7 +13,7 @@ jobs:
       fail-fast: false
       matrix:
         os:
-          - "ubuntu-24.04"
+          - "ubuntu-slim"
           - "ubuntu-24.04-arm"
           - "macos-15"