security/cargo-audit: no longer needs libgit2

cargo-audit no longer uses libgit2 as of 0.18.0.
The port builds successfully without it.

PR:		276558

security/cargo-audit/Makefile

@@ -1,7 +1,7 @@
 PORTNAME=	cargo-audit
 DISTVERSIONPREFIX=	${PORTNAME}/v
 DISTVERSION=	0.18.3
-PORTREVISION=	3
+PORTREVISION=	4
 CATEGORIES=	security
 
 MAINTAINER=	mikael@FreeBSD.org
@@ -13,9 +13,6 @@ LICENSE_COMB=	dual
 LICENSE_FILE_APACHE20=	${WRKSRC}/LICENSE-APACHE
 LICENSE_FILE_MIT=	${WRKSRC}/LICENSE-MIT
 
-LIB_DEPENDS=	libgit2.so:devel/libgit2 \
-		libssh2.so:security/libssh2
-
 USES=		cargo localbase ssl
 USE_GITHUB=	yes
 GH_ACCOUNT=	RustSec