fix: use OpenBSD 6.9 compatible libc version

Author: darfink

Cargo.toml

@@ -13,7 +13,7 @@ version = "3.0.0"
 
 [dependencies]
 bitflags = "1.0"
-libc = "0.2"
+libc = "=0.2.107" # Locked for OpenBSD 6.9 compatibility
 
 [target."cfg(any(target_os = \"macos\", target_os = \"ios\"))".dependencies]
 mach = "0.3"
@@ -22,4 +22,4 @@ mach = "0.3"
 winapi = { version = "0.3", features = ["basetsd", "minwindef", "sysinfoapi", "memoryapi", "winnt"] }
 
 [target."cfg(unix)".dev-dependencies]
-mmap = { package = "mmap-fixed", version = "0.1.5" }
+mmap = { package = "mmap-fixed", version = "0.1.5" }