Remove support for Winter v1.1

Author: LukeTowers

.github/workflows/tests.yml

@@ -17,10 +17,6 @@ jobs:
         operatingSystem: [ubuntu-latest]
         phpVersion: ['8.1', '8.2', '8.3', '8.4']
         winterBranch: ['develop']
-        include:
-          - operatingSystem: ubuntu-latest
-            phpVersion: '7.4'
-            winterBranch: '1.1'
       fail-fast: false
     name: PHP ${{ matrix.phpVersion }} / Winter ${{ matrix.winterBranch }}
     runs-on: ${{ matrix.operatingSystem }}
@@ -37,10 +33,4 @@ jobs:
         run: ./vendor/bin/parallel-lint plugins/winter/user
 
       - name: Run unit tests (develop branch)
-        if: matrix.winterBranch != '1.1'
         run: php artisan winter:test -p Winter.User -- --testdox
-
-      - name: Run unit tests (1.1 branch)
-        if: matrix.winterBranch == '1.1'
-        working-directory: plugins/winter/user
-        run: ../../../vendor/bin/phpunit --bootstrap ../../../tests/bootstrap.php --testdox