Remove unused patch

Signed-off-by: Michel Alexandre Salim <salimma@fedoraproject.org>

libbpf-cargo-downgrade-libbpf-sys.patch

@@ -1,12 +0,0 @@
-diff -Naur a/Cargo.toml b/Cargo.toml
---- a/Cargo.toml	2021-11-11 07:46:13.666336171 -0800
-+++ b/Cargo.toml	2021-11-11 07:46:29.139418018 -0800
-@@ -35,7 +35,7 @@
- version = "0.12"
- 
- [dependencies.libbpf-sys]
--version = "0.5.0-2"
-+version = "0.4.0-2"
- 
- [dependencies.memmap2]
- version = "0.3"