Code Quality: Remove conditions identified as always false

[arshidkv12]

Remove several conditions identified by PHPStan as always false.

• Remove the unreachable confidence check in wp-admin/install.php.
• Remove the unused exception state handling in wp-includes/template.php.
• Remove the always-true interim-login conditional in wp-login.php.
• Remove the corresponding PHPStan baseline entries.

Trac ticket: https://core.trac.wordpress.org/ticket/65817

Use of AI Tools

AI assistance: Yes
Tool(s): ChatGPT
Model(s): GPT-5.6 Luna
Used for: Reviewing the changes and drafting the commit message and pull request description. The final implementation was reviewed and edited by me.

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Props arshidkv12, sergeybiryukov.

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[SergeyBiryukov]

Thanks for the PR!

• The conditional in wp-admin/install.php should not be removed, it's intentionally there to check if PHP is running, see r13428.
• The change in wp-includes/template.php is not quite clear to me at the moment, could use some more investigation.
• Good catch on the interim-login conditional in wp-login.php, committed in r63930.

P.S. Please include a Trac ticket URL in the PR description, so that it is linked to the correct ticket for easier review. I've edited this PR as an example. Thanks!

[arshidkv12]

Thank you. I’ll add the tracking URL in the next PR.