fix(@angular-devkit/build-angular): disable declaration and declarationMap

When building an application or testing a library. TypeScript declarations are not needed.

Closes #20103

(cherry picked from commit 2ef3949)

Author: alan-agius4

packages/angular_devkit/build_angular/src/webpack/configs/typescript.ts

@@ -60,6 +60,8 @@ function createIvyPlugin(
 
   const compilerOptions: CompilerOptions = {
     sourceMap: buildOptions.sourceMap.scripts,
+    declaration: false,
+    declarationMap: false,
   };
 
   if (buildOptions.preserveSymlinks !== undefined) {