fix(ivy): ensure @nocollapse is added to static fields (#28050)

ngtsc has a hack to add @nocollapse jsdoc annotations to generated static
fields. This hack is currently broken (likely due to a TypeScript change
in the way writeFile() works).

This commit fixes the hack and introduces an ngtsc_spec test to ensure it
does not regress again.

PR Close #28050

packages/compiler-cli/src/ngtsc/program.ts

@@ -227,7 +227,7 @@ export class NgtscProgram implements api.Program {
           if (fileName.endsWith('.d.ts')) {
             data = sourceFiles.reduce(
                 (data, sf) => this.compilation !.transformedDtsFor(sf.fileName, data), data);
-          } else if (this.closureCompilerEnabled && fileName.endsWith('.ts')) {
+          } else if (this.closureCompilerEnabled && fileName.endsWith('.js')) {
             data = nocollapseHack(data);
           }
           this.host.writeFile(fileName, data, writeByteOrderMark, onError, sourceFiles);