fix: packaging .d.ts files (#6327)

* fix: dts files not being properly included

* fix: hand crafted declaration files pointing to the wrong things

scripts/gulpfiles/package_tasks.js

@@ -389,7 +389,7 @@ function packageDTS() {
     'typings/msg/msg.d.ts',
   ];
   return gulp.src(handwrittenSrcs, {base: 'typings'})
-      .pipe(gulp.src(`${BUILD_DIR}/${TYPINGS_BUILD_DIR}/**/*.d.ts`))
+      .pipe(gulp.src(`${TYPINGS_BUILD_DIR}/**/*.d.ts`))
       .pipe(gulp.replace('AnyDuringMigration', 'any'))
       .pipe(gulp.dest(RELEASE_DIR));
 };