chore(deps): update dependency polyfill to 9.7.0 (#4278)

Co-authored-by: Renovate Bot <renovate@whitesourcesoftware.com>

Author: thomhurst

TUnit.Core/TUnit.Core.targets

@@ -8,7 +8,7 @@
 
     <!-- Auto-include Polyfill package for compile-time type generation -->
     <PropertyGroup>
-        <_TUnitPolyfillVersion>9.6.0</_TUnitPolyfillVersion>
+        <_TUnitPolyfillVersion>9.7.0</_TUnitPolyfillVersion>
         <_TUnitNeedsPolyfill Condition="'$(TargetFramework)' == 'netstandard2.0' or '$(TargetFramework)' == 'netstandard2.1' or '$(TargetFrameworkIdentifier)' == '.NETFramework'">true</_TUnitNeedsPolyfill>
     </PropertyGroup>