user/py3-virtualenv: add cmd:which to checkdepends

user/py3-virtualenv/APKBUILD

@@ -10,7 +10,7 @@ arch="noarch"
 license="MIT"
 depends="python3"
 makedepends="python3-dev"
-checkdepends="py3-pytest py3-setuptools"
+checkdepends="py3-pytest py3-setuptools cmd:which"
 source="$pkgname-$pkgver.tar.gz::https://files.pythonhosted.org/packages/source/${_pkgname:0:1}/$_pkgname/$_pkgname-$pkgver.tar.gz
 	test-python3.patch"
 builddir="$srcdir/$_pkgname-$pkgver"