scx_pandemonium: add missing crates.io metadata

Add description and license fields required for crates.io publishing.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: htejun

scheds/rust/scx_pandemonium/Cargo.toml

@@ -2,6 +2,8 @@
 name = "scx_pandemonium"
 version = "5.4.13"
 edition = "2021"
+description = "A behavioral, adaptive sched_ext scheduler with three-tier classification, L2 affinity, and process learning"
+license = "GPL-2.0-only"
 
 [dependencies]
 libbpf-rs = { version = "=0.26.1" }