fix: coding-standard follow-ups for the 8.2 cs-check run

- Add missing `use function assert;` import in GlobTypeMapperCache so the
  new assertion satisfies the Slevomat no-fallback-global-function rule.
- Exclude SlevomatCodingStandard.TypeHints.ClassConstantTypeHint: the
  rule expects PHP 8.3 typed class constants, but our minimum supported
  PHP is 8.2 so the rule can't be satisfied. Re-enable when min PHP
  lifts to 8.3.

Author: oojacoboo

phpcs.xml.dist

@@ -29,6 +29,9 @@
         <exclude name="Squiz.Commenting.FunctionComment.InvalidNoReturn" />
         <exclude name="Generic.Formatting.MultipleStatementAlignment" />
         <exclude name="Squiz.Functions.MultiLineFunctionDeclaration.NewlineBeforeOpenBrace" />
+        <!-- Requires PHP 8.3 typed class constants; our minimum supported PHP is 8.2 so this
+             rule can't be satisfied without a runtime bump. Re-enable when min PHP >= 8.3. -->
+        <exclude name="SlevomatCodingStandard.TypeHints.ClassConstantTypeHint" />
     </rule>
 
     <!-- Do not align assignments -->

src/Mappers/GlobTypeMapperCache.php

@@ -7,6 +7,7 @@
 use ReflectionClass;
 
 use function array_keys;
+use function assert;
 
 /**
  * The cached results of a GlobTypeMapper