Fix ShellCheck warning re: alias expansion

Author: jrflat

.github/workflows/scripts/install-and-build-with-sdk.sh

@@ -502,7 +502,7 @@ build() {
         log "Running Swift build with Static Linux Swift SDK"
 
         local sdk_name="${STATIC_LINUX_SDK_TAG}_static-linux-0.0.1"
-        alias swift="$SWIFT_EXECUTABLE_FOR_STATIC_LINUX_SDK"
+        alias swift='$SWIFT_EXECUTABLE_FOR_STATIC_LINUX_SDK'
         local build_command="$SWIFT_BUILD_COMMAND --swift-sdk $sdk_name"
         if [[ -n "$SWIFT_BUILD_FLAGS" ]]; then
             build_command="$build_command $SWIFT_BUILD_FLAGS"
@@ -526,7 +526,7 @@ build() {
             local sdk_name="${WASM_SDK_TAG}_wasm"
         fi
 
-        alias swift="$SWIFT_EXECUTABLE_FOR_WASM_SDK"
+        alias swift='$SWIFT_EXECUTABLE_FOR_WASM_SDK'
         local build_command="$SWIFT_BUILD_COMMAND --swift-sdk $sdk_name"
         if [[ -n "$SWIFT_BUILD_FLAGS" ]]; then
             build_command="$build_command $SWIFT_BUILD_FLAGS"