Update inspect-ai installation in workflow and dependencies

Moved inspect-ai from pyproject.toml test dependencies to explicit installation in the GitHub Actions workflow. This change ensures inspect-ai is installed only during CI runs and not as a default test dependency.

Author: karangattu

.github/workflows/validate-test-generation-prompts.yaml

@@ -44,6 +44,7 @@ jobs:
         run: |
           pip install --upgrade pip
           pip install -e ".[dev,test]"
+          pip install inspect-ai
 
       - name: Cache Playwright browsers
         uses: actions/cache@v4

pyproject.toml

@@ -93,7 +93,6 @@ test = [
     "pyarrow-stubs",
     "chatlas[anthropic]",
     "chatlas[openai]",
-    "inspect-ai",
 ]
 dev = [
     "black>=24.0",