Update ruby/setup-ruby action to v1.206.0

Author: renovate[bot]

.github/workflows/gem-push.yml

@@ -20,7 +20,7 @@ jobs:
     # To automatically get bug fixes and new Ruby versions for ruby/setup-ruby,
     # change this to (see https://github.com/ruby/setup-ruby#versioning):
     # uses: ruby/setup-ruby@v1
-      uses: ruby/setup-ruby@c04af2bb7258bb6a03df1d3c1865998ac9390972 # v1.194.0
+      uses: ruby/setup-ruby@bfefad842bb982ff05b233bcbc1571d97a87e69f # v1.206.0
       with:
         ruby-version: 2.6.x