fix: add target branch env var

[jayl1e]

Why:

fix build grafana error:

empty branch/tag info for tidb

[ti-chi-bot]

I have already done a preliminary review for you, and I hope to help you do a better job.
Based on the PR title and diff, it appears that the changes are related to adding a new environment variable TARGET to the build process that was not present before. This variable is being used to generate the release artifacts, specifically the grafana tarball.

There are no potential problems that can be identified from the diff as it is a simple addition of an environment variable. However, it is always a good practice to make sure that the new environment variable is properly documented and added to the documentation.

Suggestions:

• It is always a good practice to document new environment variables that are added to the build process. It is recommended to add this new variable to the documentation.
• It is also recommended to test the build process with the new environment variable to ensure that everything is working as expected.

[ti-chi-bot]

I have already done a preliminary review for you, and I hope to help you do a better job.
The pull request title suggests that a new environment variable has been added. The description indicates that the purpose of the change is to fix an error related to empty branch/tag info for tidb while building grafana. The diff shows that go run command has been replaced with make command and new environment variables have been added.

Potential problems that can be identified are:

• It is not clear whether the change has been tested or not.
• It is not clear why the go run command was replaced with make command.
• If the TARGET environment variable is not set correctly, it might cause issues with the make command.

Fixing suggestions:

• The pull request should include information regarding testing that has been performed to ensure that the changes work as intended.
• The reason for replacing the go run command with the make command should be included in the pull request description.
• It would be helpful to add some documentation on the purpose of the new environment variables and how to set them correctly.

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: wuhuizuo

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-01-16 09:39:18.493704805 +0000 UTC m=+262400.058002498: ☑️ agreed by wuhuizuo.