Run the workflow on Ubuntu instead to save minutes

macOS has a high multiplier 10.

Author: ShreckYe

.github/workflows/kotlin-multiplatform-ci.yml

@@ -9,7 +9,7 @@ on:
 jobs:
   check:
 
-    runs-on: macos-latest
+    runs-on: ubuntu-latest
     permissions:
       contents: read
 
@@ -29,7 +29,7 @@ jobs:
 
   dependency-submission:
 
-    runs-on: macos-latest
+    runs-on: ubuntu-latest
     permissions:
       contents: write