.NET 8.0.20

Release

What's Changed

• Update branding to 8.0.20 by @vseanreesermsft in #63106
• [release/8.0] (deps): Bump src/submodules/googletest from c67de11 to 373af2e by @dependabot[bot] in #63038
• [release/8.0] Dispose the certificate chain elements with the chain by @MackinnonBuck in #62994
• [release/8.0] Update SignalR Redis tests to use internal Docker Hub mirror by @github-actions[bot] in #63117
• [release/8.0] [SignalR] Don't throw for message headers in Java client by @github-actions[bot] in #62784
• Merging internal commits for release/8.0 by @vseanreesermsft in #63152
• [release/8.0] Update dependencies from dotnet/extensions by @dotnet-maestro[bot] in #63188
• [release/8.0] Update dependencies from dotnet/arcade by @dotnet-maestro[bot] in #63189

Full Changelog: v8.0.19...v8.0.20