Performance optimization for git push (#30104) (#30354)

Agit returned result should be from `ProcReceive` hook but not
`PostReceive` hook. Then for all non-agit pull requests, it will not
check the pull requests for every pushing `refs/pull/%d/head`.

Backport #30104

(cherry picked from commit 6e3aaa997549b83935241e486caf811793c88aea)

Conflicts:
    it is implemented differently in Forgejo, just keep the test
    in tests/integration/git_push_test.go
(cherry picked from commit b7cff17de1)

tests/integration/git_push_test.go

@@ -0,0 +1,67 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package integration
+
+import (
+	"net/url"
+	"testing"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/unittest"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/git"
+	repo_service "code.gitea.io/gitea/services/repository"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestGitPush(t *testing.T) {
+	onGiteaRun(t, testGitPush)
+}
+
+func testGitPush(t *testing.T, u *url.URL) {
+	t.Run("Push branch with options", func(t *testing.T) {
+		runTestGitPush(t, u, func(t *testing.T, gitPath string) {
+			branchName := "branch-with-options"
+			doGitCreateBranch(gitPath, branchName)(t)
+			doGitPushTestRepository(gitPath, "origin", branchName, "-o", "repo.private=true", "-o", "repo.template=true")(t)
+		})
+	})
+}
+
+func runTestGitPush(t *testing.T, u *url.URL, gitOperation func(t *testing.T, gitPath string)) {
+	user := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 2})
+	repo, err := repo_service.CreateRepository(db.DefaultContext, user, user, repo_service.CreateRepoOptions{
+		Name:          "repo-to-push",
+		Description:   "test git push",
+		AutoInit:      false,
+		DefaultBranch: "main",
+		IsPrivate:     false,
+	})
+	require.NoError(t, err)
+	require.NotEmpty(t, repo)
+
+	gitPath := t.TempDir()
+
+	doGitInitTestRepository(gitPath)(t)
+
+	oldPath := u.Path
+	oldUser := u.User
+	defer func() {
+		u.Path = oldPath
+		u.User = oldUser
+	}()
+	u.Path = repo.FullName() + ".git"
+	u.User = url.UserPassword(user.LowerName, userPassword)
+
+	doGitAddRemote(gitPath, "origin", u)(t)
+
+	gitRepo, err := git.OpenRepository(git.DefaultContext, gitPath)
+	require.NoError(t, err)
+	defer gitRepo.Close()
+
+	gitOperation(t, gitPath)
+
+	require.NoError(t, repo_service.DeleteRepositoryDirectly(db.DefaultContext, user, user.ID, repo.ID))
+}