perf: disable slang support
libs/slang2 is getting picked up from the packages feed, if the slang2
is compiled first and then if you try to compile perf, it fails
due to unmet dependency.
Fixes:
Package perf is missing dependencies for the following libraries:
libslang.so.2
Signed-off-by: Josef Schlehofer <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/19123
Signed-off-by: Hauke Mehrtens <[email protected]>