Stop setting `re2_INCLUDE_DIR`.

It was probably neither needed nor used and will start causing
problems as of CMake 3.29, which removes `PACKAGE_PREFIX_DIR`.

Fixes #488.

Change-Id: I707dc903234309698a6745d2b61279fd3b7bd6dc
Reviewed-on: https://code-review.googlesource.com/c/re2/+/62930
Reviewed-by: Paul Wankadia <junyer@google.com>
Reviewed-by: Alex Chernyakhovsky <achernya@google.com>
1 file changed