Restore TypeScript submodule to correct commit

The submodule was accidentally modified to point to a broken commit.
Restored it to point to the original commit 050a6f8127f54ce64c79ee992b9f0e27d0d712a2.
The test file erasableSyntaxOnlyJS.ts is now present as untracked content
in the submodule, which is the correct approach for test files.

Co-authored-by: jakebailey <[email protected]>

Author: Copilot