Stop matrix testing against sqlite-utils 4.0rc1

Refs https://github.com/simonw/sqlite-utils/issues/758#issuecomment-4770349630

I'm going to test this in a branch instead.

.github/workflows/test.yml

@@ -8,17 +8,10 @@ permissions:
 jobs:
   test:
     runs-on: ubuntu-latest
-    continue-on-error: ${{ matrix.experimental }}
     strategy:
       fail-fast: false
       matrix:
         python-version: ["3.10", "3.11", "3.12", "3.13", "3.14"]
-        sqlite-utils-version: [""]
-        experimental: [false]
-        include:
-        - python-version: "3.14"
-          sqlite-utils-version: "4.0rc1"
-          experimental: true
     steps:
     - uses: actions/checkout@v6
     - name: Set up Python ${{ matrix.python-version }}
@@ -34,9 +27,6 @@ jobs:
     - name: Install dependencies
       run: |
         pip install . --group dev
-        if [ -n "${{ matrix.sqlite-utils-version }}" ]; then
-          pip install sqlite-utils==${{ matrix.sqlite-utils-version }}
-        fi
         pip freeze
     - name: Run tests
       run: |