Add static SDK CI workflow (#61)

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

---------

Co-authored-by: Cory Benfield <lukasa@apple.com>

Author: rnro

.github/workflows/main.yml

@@ -17,6 +17,10 @@ jobs:
             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
+        uses: apple/swift-nio/.github/workflows/static_sdk.yml@main
+
     macos-tests:
         name: macOS tests
         uses: apple/swift-nio/.github/workflows/macos_tests.yml@main

.github/workflows/pull_request.yml

@@ -24,6 +24,10 @@ jobs:
         name: Cxx interop
         uses: apple/swift-nio/.github/workflows/cxx_interop.yml@main
 
+    static-sdk:
+        name: Static SDK
+        uses: apple/swift-nio/.github/workflows/static_sdk.yml@main
+
     macos-tests:
         name: macOS tests
         uses: apple/swift-nio/.github/workflows/macos_tests.yml@main

Sources/RawStructuredFieldValues/PseudoDecimal.swift

@@ -15,6 +15,8 @@
 import Darwin
 #elseif canImport(Glibc)
 import Glibc
+#elseif canImport(Musl)
+import Musl
 #elseif canImport(Android)
 import Android
 #else