Move requirements file for tests to the tests folder

.github/workflows/test_linux.yml

@@ -30,7 +30,7 @@ jobs:
         uses: actions/checkout@v3
       - name: Install Dependencies (pip)
         run: |
-          pip install -U -r requirements.txt -r requirements-dev.txt
+          pip install -U -r requirements.txt -r tests/requirements.txt
       - name: Run Build Commands
         run: python pkgutils.py qtlrelease sample
       - name: Run Tests

.github/workflows/test_mac.yml

@@ -26,7 +26,7 @@ jobs:
         uses: actions/checkout@v3
       - name: Install Dependencies (pip)
         run: |
-          pip install -U pyobjc -r requirements.txt -r requirements-dev.txt
+          pip install -U pyobjc -r requirements.txt -r tests/requirements.txt
       - name: Run Tests
         run: |
           export QT_QPA_PLATFORM=offscreen

.github/workflows/test_win.yml

@@ -23,7 +23,7 @@ jobs:
         uses: actions/checkout@v3
       - name: Install Dependencies (pip)
         run: |
-          pip install -U -r requirements.txt -r requirements-dev.txt
+          pip install -U -r requirements.txt -r tests/requirements.txt
       - name: Run Tests
         run: |
           pytest -v --cov=novelwriter --timeout=60