fix: use latest version of .NET Stryker (#43)

Use latest version of the `dotnet-stryker` tool after
stryker-mutator/mutation-testing-elements#2493
was fixed.

Author: vbreuss

.github/workflows/stryker.yml

@@ -23,7 +23,7 @@ jobs:
       - name: Install .NET Stryker
         shell: bash
         run: |
-          dotnet tool install dotnet-stryker --tool-path ../tools --version 3.7.1
+          dotnet tool install dotnet-stryker --tool-path ../tools
       - name: Analyze Testably.Architecture.Rules
         env:
           STRYKER_DASHBOARD_API_KEY: ${{ secrets.STRYKER_DASHBOARD_API_KEY }}