Remove unneeded URL validation

[dkotter]

What?

Remove some URL validation code that is no longer needed as we can rely on changes introduced in WP 7.0.3

Why?

We recently updated the validation we run on URLs when someone passes an image URL into our Alt Text Generation Ability. Some of the validation introduced there is no longer needed as WordPress added the same changes in v7.0.3 so this PR simplifies things a bit to rely on Core as much as possible.

How?

• Rely more on wp_http_validate_url and remove code that we no longer need
• Bump our minimum WordPress version to 7.0.3 which is where those additional fixes were added
• Remove some IPv6 checks that were dead code

Use of AI Tools

AI assistance: Yes
Tool(s): Claude Code
Model(s): Opus 5
Used for: Evaluating our current code against WordPress Core to determine what could be cleaned up. All changes tested and reviewed by me

Testing Instructions

Ensure the Alt Text Generation feature still works as expected.

If desired, directly invoke the Alt Text Generation Ability with a custom image_url passed in to ensure that works

Changelog Entry

Changed - Bump our minimum WordPress version to 7.0.3.
Removed - Unnecessary URL validation that is now handled by WordPress core.

[github-actions]

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Co-authored-by: dkotter <dkotter@git.wordpress.org>
Co-authored-by: justlevine <justlevine@git.wordpress.org>

To understand the WordPress project's expectations around crediting contributors, please review the Contributor Attribution page in the Core Handbook.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 81.47%. Comparing base (eca57d2) to head (286dd11).

Additional details and impacted files

@@              Coverage Diff              @@
##             develop    #1011      +/-   ##
=============================================
- Coverage      81.50%   81.47%   -0.04%     
+ Complexity      2923     2907      -16     
=============================================
  Files            122      122              
  Lines          11653    11638      -15     
=============================================
- Hits            9498     9482      -16     
- Misses          2155     2156       +1     

Flag	Coverage Δ
unit	81.47% <100.00%> (-0.04%)	⬇️

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[dkotter]

Note there's currently an issue in wp-env where the PHP package it loads for PHP 7.4 and 8.0 has been shutdown and so any environment that uses those versions won't start up. This causes 6 failing workflows here (and on all other PRs). Ideally this is fixed upstream in Gutenberg but in the meantime, we could drop PHP 7.4 and 8.0 from our test matrix if we want green tests across the board.

[justlevine]

Note there's currently an issue in wp-env where the PHP package it loads for PHP 7.4 and 8.0 has been shutdown and so any environment that uses those versions won't start up. This causes 6 failing workflows here (and on all other PRs). Ideally this is fixed upstream in Gutenberg but in the meantime, we could drop PHP 7.4 and 8.0 from our test matrix if we want green tests across the board.

PS: @dkotter this how @galatanovidiu is handling it in WordPress/mcp-adapter

• Fix wp-env builds for PHP 7.4 and 8.0 after Debian bullseye end of life mcp-adapter#322