refactor(upgrade): use Bazel packages to avoid symlinks in the source (#29466)

Previously we had to share code between upgrade/dynamic and upgrade/static
by symlinking the `src` folder, which allowed both packages to access
the upgrade/common files.

These symlinks are always problematic on Windows, where we had to run
a script to re-link them, and restore them.

This change uses Bazel packages to share the `upgrade/common` code,
which avoids the need for symlinking the `src` folder.

Also, the Windows specific scripts that fixup the symlinks have also
been removed as there is no more need for them.

PR Close #29466

aio/README.md

@@ -41,16 +41,6 @@ Here are the most important tasks you might need to use:
   - `yarn example-e2e --filter=foo` - limit e2e tests to those containing the word "foo"
   - `yarn example-e2e --setup --local` - run e2e tests with the local version of Angular contained in the "dist" folder
 
-## Developing on Windows
-The `packages/` directory may contain Linux-specific symlinks, which are not recognized by Windows.
-These unresolved links cause the docs generation process to fail because it cannot locate certain files.
-
-> Hint: The following steps require administration rights or [Windows Developer Mode](https://docs.microsoft.com/en-us/windows/uwp/get-started/enable-your-device-for-development) enabled!
-
-To fix this problem, run `scripts/windows/create-symlinks.sh`. This command creates temporary files where the symlinks used to be. Make sure not to commit those files with your documentation changes.
-When you are done making and testing your documentation changes, you can restore the original symlinks and delete the temporary files by running `scripts/windows/remove-symlinks.sh`.
-
-It's necessary to remove the temporary files, because otherwise they're displayed as local changes in your git working copy and certain operations are blocked.
 
 ## Using ServiceWorker locally