Drop ebuild patches

None of these are necessary anymore.  They do not apply cleanly to
current versions of ebuilds in Gentoo's repository, causing builds to
fail.

Going forward, I think it will be better to maintain patched ebuilds in
the Aimee OS repository, rather than patching them at build time.

Makefile

@@ -8,8 +8,7 @@ update.tar: $(IMAGESDIR)/update.tar.zstd
 
 $(O)/.prepared: \
 		prepare.sh \
-		setup-local-repo.sh \
-		$(shell find patches/ebuilds -type f)
+		setup-local-repo.sh
 	./prepare.sh
 	./setup-local-repo.sh
 	mkdir -p $(O)