Update CI to PHP 8.5 stable and fix test file naming (#258)

## Summary

  - Update CI matrix from PHP 8.5.0alpha4 to 8.5 stable
- Rename `php84_exit.phpt` to `php85_exit.phpt` for consistency with
other PHP 8.5 tests
  - Update `package.xml` to reflect the renamed test file

## Context

PHP 8.5 was officially released on November 20, 2025. This PR updates
the CI workflow to test against the stable release instead of the alpha
version.

The test file `php84_exit.phpt` was incorrectly named - it tests the PHP
8.5 feature where `exit` is represented as `AST_CALL`, so it should
follow the `php85_*` naming convention used by the other PHP 8.5 tests
(`php85_clone.phpt`, `php85_pipe_operator.phpt`,
`php85_void_cast.phpt`).

Signed-off-by: Marjo Wenzel van Lier <[email protected]>

Author: MarjovanLier

.github/workflows/main.yml

@@ -35,7 +35,7 @@ jobs:
          - PHP_VERSION: '8.2'
          - PHP_VERSION: '8.3'
          - PHP_VERSION: '8.4'
-         - PHP_VERSION: '8.5.0alpha4'
+         - PHP_VERSION: '8.5'
 
     # Steps represent a sequence of tasks that will be executed as part of the job
     steps:

package.xml

@@ -124,12 +124,12 @@
       <file name="php82_encaps_list.phpt" role="test" />
       <file name="php82_readonly_class.phpt" role="test" />
       <file name="php84_dim_alternative_syntax.phpt" role="test" />
-      <file name="php84_exit.phpt" role="test" />
+      <file name="php84_property_hook.phpt" role="test" />
       <file name="php84_property_hook2.phpt" role="test" />
       <file name="php84_property_hook3.phpt" role="test" />
       <file name="php84_property_hook4.phpt" role="test" />
-      <file name="php84_property_hook.phpt" role="test" />
       <file name="php85_clone.phpt" role="test" />
+      <file name="php85_exit.phpt" role="test" />
       <file name="php85_pipe_operator.phpt" role="test" />
       <file name="php85_void_cast.phpt" role="test" />
       <file name="prop_doc_comments.phpt" role="test" />