fix: skip --platform and --output for platformTag builds

The devcontainer CLI rejects --platform for docker-compose-based
devcontainers. When platformTag is set, the runner is already the
correct native architecture, so --platform is unnecessary.

Author: tgenov

github-action/dist/index.js

@@ -2253,10 +2253,10 @@ function runMain() {
                     workspaceFolder,
                     configFile,
                     imageName: fullImageNameArray,
-                    platform,
+                    platform: platformTag ? undefined : platform,
                     additionalCacheFroms: cacheFrom,
                     userDataFolder,
-                    output: buildxOutput,
+                    output: platformTag ? undefined : buildxOutput,
                     noCache,
                     cacheTo,
                 };

github-action/dist/index.js.map

@@ -133,10 +133,10 @@ export async function runMain(): Promise<void> {
 				workspaceFolder,
 				configFile,
 				imageName: fullImageNameArray,
-				platform,
+				platform: platformTag ? undefined : platform,
 				additionalCacheFroms: cacheFrom,
 				userDataFolder,
-				output: buildxOutput,
+				output: platformTag ? undefined : buildxOutput,
 				noCache,
 				cacheTo,
 			};