Add static SDK CI workflow (#49)

Add static SDK CI workflow which runs on commits to PRs, merges to main
and daily on main.

Author: rnro

.github/workflows/main.yml

@@ -16,3 +16,8 @@ jobs:
       linux_6_0_arguments_override: "-Xswiftc -warnings-as-errors --explicit-target-dependency-import-check error -Xswiftc -require-explicit-sendable"
       linux_nightly_next_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -require-explicit-sendable"
       linux_nightly_main_arguments_override: "--explicit-target-dependency-import-check error -Xswiftc -require-explicit-sendable"
+
+  static-sdk:
+    name: Static SDK
+    # Workaround https://github.com/nektos/act/issues/1875
+    uses: apple/swift-nio/.github/workflows/static_sdk.yml@main

.github/workflows/pull_request.yml

@@ -28,3 +28,8 @@ jobs:
   swift-6-language-mode:
     name: Cxx interop
     uses: apple/swift-nio/.github/workflows/swift_6_language_mode.yml@main
+
+  static-sdk:
+    name: Static SDK
+    # Workaround https://github.com/nektos/act/issues/1875
+    uses: apple/swift-nio/.github/workflows/static_sdk.yml@main