Fix migration v292 (#30153)

Fix https://github.com/go-gitea/gitea/pull/29874#discussion_r1542227686

- The migration of v292 will miss many projects. These projects will
have no default board. This PR introduced a new migration number and
removed v292 migration.

- This PR also added the missed transactions on project-related
operations.

- Only `SetDefaultBoard` will remove duplicated defaults but not in
`GetDefaultBoard`

models/migrations/v1_22/v293_test.go

@@ -0,0 +1,44 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package v1_22 //nolint
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/migrations/base"
+	"code.gitea.io/gitea/models/project"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_CheckProjectColumnsConsistency(t *testing.T) {
+	// Prepare and load the testing database
+	x, deferable := base.PrepareTestEnv(t, 0, new(project.Project), new(project.Board))
+	defer deferable()
+	if x == nil || t.Failed() {
+		return
+	}
+
+	assert.NoError(t, CheckProjectColumnsConsistency(x))
+
+	// check if default board was added
+	var defaultBoard project.Board
+	has, err := x.Where("project_id=? AND `default` = ?", 1, true).Get(&defaultBoard)
+	assert.NoError(t, err)
+	assert.True(t, has)
+	assert.Equal(t, int64(1), defaultBoard.ProjectID)
+	assert.True(t, defaultBoard.Default)
+
+	// check if multiple defaults, previous were removed and last will be kept
+	expectDefaultBoard, err := project.GetBoard(db.DefaultContext, 2)
+	assert.NoError(t, err)
+	assert.Equal(t, int64(2), expectDefaultBoard.ProjectID)
+	assert.False(t, expectDefaultBoard.Default)
+
+	expectNonDefaultBoard, err := project.GetBoard(db.DefaultContext, 3)
+	assert.NoError(t, err)
+	assert.Equal(t, int64(2), expectNonDefaultBoard.ProjectID)
+	assert.True(t, expectNonDefaultBoard.Default)
+}