* gnu/packages/racket.scm (racket)[source](patches): Remove
"racket-store-checksum-override.patch", which is no longer needed since
we stopped injecting store paths into Racket files in commit 834aa48:
see <https://issues.guix.gnu.org/47180>.
* gnu/packages/patches/racket-store-checksum-override.patch: Delete file.
* gnu/local.mk (dist_patch_DATA): Remove it.
Signed-off-by: Ludovic Courtès <ludo@gnu.org>