fix(windows): switch build to VS16 (windows-2019) to match php.net builds

[hamptokr]

The official PHP builds for windows from php.net use windows-2019 (VS16). That's why windows users see the following mismatch error when trying to load the module:

Warning: PHP Startup: Can't load module 'php_libsql.dll' as it's linked with 14.40, but the core is linked with 14.29 in Unknown on line 0

Here's a link to the github action windows config the official PHP Interpreter uses: https://github.com/php/php-src/blob/93c3ebd209f2111f986a0db4c7b6ddb7284fd71c/.github/workflows/nightly.yml#L886

This PR updates this project's github action to match the PHP interpreter project

PR Checklist

Please check if your PR fulfills the following requirements:

• [ ] The commit message follows our guidelines: https://github.com/darkterminal/libsql-extension/blob/main/CONTRIBUTING.md#commit
• [ ] Tests for the changes have been added (for bug fixes / features)
• [ ] Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• [x] Bugfix
• [ ] Feature
• [ ] Code style update (formatting, local variables)
• [ ] Refactoring (no functional changes, no api changes)
• [ ] Build related changes
• [ ] CI related changes
• [ ] Documentation content changes
• [ ] Other... Please describe:

What is the current behavior?

Issue Number: N/A

What is the new behavior?

Does this PR introduce a breaking change?

• [ ] Yes
• [ ] No

Other information

[darkterminal]

Only few characters and it's make me feel so bad (stupid) :crying_cat_face:

But, your PR it's :1st_place_medal: for me and also you need also adjust the docs