testing/broot: build with system-provided libgit2

testing/broot/APKBUILD

@@ -7,10 +7,12 @@ pkgdesc="New way to see and navigate directory trees"
 url="https://github.com/Canop/broot"
 arch="all !s390x !mips !mips64 !ppc64le" # blocked by cargo, ppc64le: build failure
 license="MIT"
-makedepends="cargo"
+makedepends="cargo libgit2-dev"
 subpackages="$pkgname-doc"
 source="$pkgname-$pkgver.tar.gz::https://crates.io/api/v1/crates/broot/$pkgver/download"
 
+export LIBGIT2_SYS_USE_PKG_CONFIG=1  # Use system libgit2
+
 build() {
 	cargo build --release --locked
 }