note regarding origin of tsickle files

Author: pcj

vendor/tsickle/README.md

@@ -1,8 +1,7 @@
 # Tsickle - TypeScript to Closure Translator
 
-The tsickle repository is unsupported and will not be updated. It has been [officially unsupported](https://github.com/angular/tsickle/commit/3bf8d97c6bd53a920eb4f9b4d18cb584ead48e5a) since November 2022, has not seen any new commits to master since December 2023, and will be frozen starting May 2024. We generally cannot support using tsickle to integrate with Closure Compiler outside of the Google ecosystem due to the complexity of the toolchain.
-
-This repository will remain publicly available to fork.
-
-Previous version of this README can be found [here](https://github.com/angular/tsickle/blob/3bf8d97c6bd53a920eb4f9b4d18cb584ead48e5a/README.md).
+This is a vendored copy of <[https://](https://github.com/angular/tsickle/commit/2129d363a0562b7ca1acdf55945c22b7d16539a3)> with the following changes:
 
+- `BUILD.bazel` file added to expose the `tsconfig.json` file.
+- `src/BUILD.bazel` file added to expose the srcs as a `ts_project`.
+- Change to `src/googmodule.ts`: the function `tryFindAmbientModuleWithoutAugmentations` seems to be an angular-google-internal function.  It has been stubbed out to always return `undefined`.