testutil: add helper function for depsolving pkgset with DNF4

This will be useful for testing SBOM implementations.

Signed-off-by: Tomáš Hozza <thozza@redhat.com>

test/mod/test_testutil_dnf4.py

@@ -0,0 +1,11 @@
+import os.path
+
+import pytest
+
+testutil_dnf4 = pytest.importorskip("osbuild.testutil.dnf4")
+
+
+def test_depsolve_pkgset():
+    pkgset = testutil_dnf4.depsolve_pkgset([os.path.abspath("./test/data/testrepos/baseos")], ["bash"])
+    assert len(pkgset) == 15
+    assert "bash" in [pkg.name for pkg in pkgset]