fix: overwrite configEnv.mode if the user explicitly set mode option (fix #4441)

[hyf0]

Fix #4441 .

Description

without this PR. the mode and configEnv.mode variables will be inconsistent in some cases.

Additional context

I don't quite understand how to add a test for such case.

---

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

Before submitting the PR, please make sure you do the following

• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the Commit Convention.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.

[patak-dev]

This looks ok here. But I'm a bit confused by the logic of the previous line.
According to https://github.com/iheyunfei/vite/blob/a7a9a361cf13670c2e241620ddaf15021eda26b5/packages/vite/src/node/config.ts#L103, the inline config mode should be the one winning over the config file mode, and that is not the case here AFAICS. @AlexandreBonaventure I think you were using this feature, does it works correctly for you when overriding --mode in the CLI? It should win over the one you used in your config file.

@iheyunfei as a note, it would be good to have an issue for this kind of PR with a reproduction for reference. It is easier to merge PRs when we have a clear bug that they are fixing.

[hyf0]

@patak-js Yes, I'm going to raise an issue. For your question, I look down the codes and It won't win over the mode in the config file.

[patak-dev]

Ya, looks like there are other issues to fix here

[hyf0]

Fix it too. After looking back, I found I just solve inconstancy in some cases. Still, there is a case that could not be easily fixed. I will open another issue to describe it.