jobqueue: remove testjobqueue

testjobqueue did not implement the JobQueue interface correctly (noted
in its package comment), making it impossible to write tests for
JobQueue itself.

Replace its use everywhere with fsjobqueue operating on a temporary
directory.

internal/client/unit_test.go

@@ -11,6 +11,7 @@ import (
 	"net"
 	"net/http"
 	"os"
+	"path"
 	"testing"
 
 	"github.com/osbuild/osbuild-composer/internal/distro/fedoratest"
@@ -37,7 +38,11 @@ func executeTests(m *testing.M) int {
 	}
 
 	// Create a mock API server listening on the temporary socket
-	fixture := rpmmd_mock.BaseFixture()
+	err = os.Mkdir(path.Join(tmpdir, "/jobs"), 0755)
+	if err != nil {
+		panic(err)
+	}
+	fixture := rpmmd_mock.BaseFixture(path.Join(tmpdir, "/jobs"))
 	rpm := rpmmd_mock.NewRPMMDMock(fixture)
 	distro := fedoratest.New()
 	arch, err := distro.GetArch("x86_64")