GH Actions: Remove architecture from inputs

Should clean up warnings like this:

> Unexpected input(s) 'architecture', valid inputs are ['ruby-version',
> 'rubygems', 'bundler', 'bundler-cache', 'working-directory',
> 'cache-version']

.github/workflows/go-spectest.yml

@@ -35,7 +35,6 @@ jobs:
         uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{matrix.ruby}}
-          architecture: 'x64'
       - name: Setup ruby vagrant
         run: |
           gem install --no-document bundler

.github/workflows/go-testing.yml

@@ -39,7 +39,6 @@ jobs:
         uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{matrix.ruby}}
-          architecture: 'x64'
       - name: Setup ruby vagrant
         run: |
           gem install --no-document bundler

.github/workflows/testing.yml

@@ -39,6 +39,5 @@ jobs:
         uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{matrix.ruby}}
-          architecture: 'x64'
       - name: Run Tests
         run: .ci/test.sh