DOCS-9218: Upgrade PCRE to 8.39

Author: i80and

source/reference/operator/query/regex.txt

@@ -17,7 +17,7 @@ Definition
 
    Provides regular expression capabilities for pattern matching
    *strings* in queries. MongoDB uses Perl compatible regular
-   expressions (i.e. "PCRE" ) version 8.38 with UTF-8 support.
+   expressions (i.e. "PCRE" ) version 8.39 with UTF-8 support.
 
    To use :query:`$regex`, use one of the following syntax: