Address SonarLint findings in SectionPairDocumentValidator class

source/ls-std/io/section-pair/validator/SectionPairDocumentValidator.cpp

@@ -3,7 +3,7 @@
 * Company:         Lynar Studios
 * E-Mail:          webmaster@lynarstudios.com
 * Created:         2023-02-21
-* Changed:         2023-02-23
+* Changed:         2023-05-16
 *
 * */
 
@@ -27,7 +27,7 @@ SectionPairDocumentValidator::~SectionPairDocumentValidator() noexcept = default
 bool SectionPairDocumentValidator::isValid()
 {
   string validationRegex = SectionPairDocumentValidator::_getValidationRegex();
-  static regex documentRegex = regex{"^" + validationRegex + "$"};
+  static auto documentRegex = regex{"^" + validationRegex + "$"};
 
   return regex_match(this->document, documentRegex);
 }