Bump Google.Protobuf from 3.9.1 to 3.15.0 in /src/Catalyst.Abstractions#1336

dependabot[bot] wants to merge 1 commit intomastercatalyst-network/Catalyst:masterfrom

dependabot/nuget/src/Catalyst.Abstractions/Google.Protobuf-3.15.0catalyst-network/Catalyst:dependabot/nuget/src/Catalyst.Abstractions/Google.Protobuf-3.15.0Copy head branch name to clipboard