Bump Microsoft.CodeAnalysis.FxCopAnalyzers from 2.6.2 to 2.6.3 in /src

Bumps [Microsoft.CodeAnalysis.FxCopAnalyzers](https://github.com/dotnet/roslyn-analyzers) from 2.6.2 to 2.6.3.
- [Release notes](https://github.com/dotnet/roslyn-analyzers/releases)
- [Commits](dotnet/roslyn-analyzers@v2.6.2...v2.6.3)

Signed-off-by: dependabot[bot] <support@dependabot.com>

src/Cake.Issues.PullRequests.AppVeyor/Cake.Issues.PullRequests.AppVeyor.csproj

@@ -26,7 +26,7 @@
     <PackageReference Include="Cake.Core" Version="0.28.0" />
     <PackageReference Include="Cake.Issues" Version="0.6.1" />
     <PackageReference Include="Cake.Issues.PullRequests" Version="0.6.0" />
-    <PackageReference Include="Microsoft.CodeAnalysis.FxCopAnalyzers" Version="2.6.2" />
+    <PackageReference Include="Microsoft.CodeAnalysis.FxCopAnalyzers" Version="2.6.3" />
     <PackageReference Include="StyleCop.Analyzers" Version="1.1.0-beta009" />
   </ItemGroup>