Include the GITHUB_TOKEN/GITEA_TOKEN secret for fork pull requests (go-gitea#26759)

Backport go-gitea#26759

Include `GITHUB_TOKEN`/`GITEA_TOKEN` secrets for actions triggered by
pull requests

This makes it consistent with the environment variables which you can
already access

```shell
echo env: $GITHUB_TOKEN
echo expression: ${{ secrets.GITHUB_TOKEN }}
```
before

![image](https://github.com/go-gitea/gitea/assets/35262707/b6f750f6-3995-40f0-b8aa-df01e7997c37)
after

![image](https://github.com/go-gitea/gitea/assets/35262707/ab74464b-7638-458a-afd5-f39e6101d2cf)

---------

Co-authored-by: Jason Song <[email protected]>
Co-authored-by: Giteabot <[email protected]>

Author: 3 people

routers/api/actions/runner/utils.go

@@ -53,8 +53,12 @@ func pickTask(ctx context.Context, runner *actions_model.ActionRunner) (*runnerv
 
 func getSecretsOfTask(ctx context.Context, task *actions_model.ActionTask) map[string]string {
 	secrets := map[string]string{}
+
+	secrets["GITHUB_TOKEN"] = task.Token
+	secrets["GITEA_TOKEN"] = task.Token
+
 	if task.Job.Run.IsForkPullRequest {
-		// ignore secrets for fork pull request
+		// ignore secrets for fork pull request, except GITHUB_TOKEN and GITEA_TOKEN which are automatically generated.
 		return secrets
 	}
 
@@ -78,13 +82,6 @@ func getSecretsOfTask(ctx context.Context, task *actions_model.ActionTask) map[s
 		}
 	}
 
-	if _, ok := secrets["GITHUB_TOKEN"]; !ok {
-		secrets["GITHUB_TOKEN"] = task.Token
-	}
-	if _, ok := secrets["GITEA_TOKEN"]; !ok {
-		secrets["GITEA_TOKEN"] = task.Token
-	}
-
 	return secrets
 }