Remove chirb.it support due to service closure

The chirb.it audio sharing service is no longer accessible (connection failure). This commit removes all related code and test files.

Changes:
- Remove chirb.it from oEmbed providers list
- Remove test case from PagesTest
- Delete cached responses and test fixtures

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: uzulla

src/resources/oembed.php

@@ -181,9 +181,6 @@
     'http://embed.chartblocks.com/1.0/oembed' => [
         '|^https?://public\\.chartblocks\\.com/c/.*$|i',
     ],
-    'http://chirb.it/oembed.json' => [
-        '|^https?://chirb\\.it/.*$|i',
-    ],
     'https://chroco.ooo/embed' => [
         '|^https?://chroco\\.ooo/mypage/.*$|i',
         '|^https?://chroco\\.ooo/story/.*$|i',

tests/PagesTest.php

@@ -27,7 +27,6 @@ public function urlDataProvider(): array
             ['http://live.amcharts.com/czNjJ'],
             ['https://www.aol.com/video/view/pile-of-recovering-foster-kittens-is-purrfect/595fe75985eb42109b69bedb/'],
             ['http://jeanjean.bandcamp.com/track/coquin-l-l-phant'],
-            ['http://chirb.it/7A9L9B'],
             ['http://codepen.io/Zhouzi/pen/JoRazP'],
             ['http://www.dailymotion.com/video/xy0wd'],
             ['http://www.deviantart.com/art/Misty-510056679'],