push: Fix word matching without wildcards

Don't match non-ASCII alphanumeric characters

crates/ruma-common/CHANGELOG.md

@@ -4,8 +4,8 @@ Bug fixes:
 
 * Expose `MatrixIdError`, `MatrixToError`, `MatrixUriError` and `MxcUriError` at
   the crate root
-* Allow wildcards for push conditions on `content.body`
-  * The spec clarified the behavior of the `event_match` condition:
+* Fix matching of `event_match` condition
+  * The spec clarified its behavior:
     <https://github.com/matrix-org/matrix-spec-proposals/pull/3690> 
 
 Breaking changes:

crates/ruma-common/src/push/condition.rs

@@ -155,7 +155,7 @@ trait CharExt {
 
 impl CharExt for char {
     fn is_word_char(&self) -> bool {
-        self.is_alphanumeric() || *self == '_'
+        self.is_ascii_alphanumeric() || *self == '_'
     }
 }