[DB] Add test for TestEnsureUpToDate (squash)

- Add a test for the behavior of `EnsureUpToDate`, to ensure it will
error when needed and succeed when the forgejo version is up to date.
- Add forgejo_migrations package to GO_TEST_PACKAGES, to avoid running
it with `test-unit` and instead test it with `test-*-migration`.

(cherry picked from commit b172a50691)

models/forgejo_migrations/migrate_test.go

@@ -0,0 +1,39 @@
+// Copyright 2023 The Forgejo Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package forgejo_migrations //nolint:revive
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/models/migrations/base"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// TestEnsureUpToDate tests the behavior of EnsureUpToDate.
+func TestEnsureUpToDate(t *testing.T) {
+	x, deferable := base.PrepareTestEnv(t, 0, new(ForgejoVersion))
+	defer deferable()
+	if x == nil || t.Failed() {
+		return
+	}
+
+	// Ensure error if there's no row in Forgejo Version.
+	err := EnsureUpToDate(x)
+	assert.Error(t, err)
+
+	// Insert 'good' Forgejo Version row.
+	_, err = x.InsertOne(&ForgejoVersion{ID: 1, Version: ExpectedVersion()})
+	assert.NoError(t, err)
+
+	err = EnsureUpToDate(x)
+	assert.NoError(t, err)
+
+	// Modify forgejo version to have a lower version.
+	_, err = x.Exec("UPDATE `forgejo_version` SET version = ? WHERE id = 1", ExpectedVersion()-1)
+	assert.NoError(t, err)
+
+	err = EnsureUpToDate(x)
+	assert.Error(t, err)
+}