CI: Update GitHub Actions runs-on to Ubuntu 22.04

Author: kateinoigakukun

.github/workflows/main.yml

@@ -104,7 +104,7 @@ jobs:
             wasi-swift-sdk-id: DEVELOPMENT-SNAPSHOT-2024-10-15-a-wasm32-unknown-wasi
             wasi-swift-sdk-checksum: "229cd9d3b0ed582c7ef7c3064888ad78764e4743b5a770df92554a94513f53fb"
 
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     name: "build-linux (${{ matrix.swift }})"
 
     steps:
@@ -221,7 +221,7 @@ jobs:
           swift test @ExtraFlags
 
   build-cmake:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     container:
       image: swift:5.8-focal
     steps: