ci: add dev requirements file and update workflow

Create requirements-dev.txt with pylint and pyright. The bot-bottle
project itself has no runtime dependencies. Update workflow to use
the requirements file for pip caching.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

.gitea/workflows/lint.yml

@@ -18,11 +18,12 @@ jobs:
         with:
           python-version: '3.12'
           cache: 'pip'
+          cache-dependency-path: requirements-dev.txt
 
-      - name: Install dependencies
+      - name: Install dev dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install pylint pyright
+          pip install -r requirements-dev.txt
 
       - name: Run pylint
         run: |

requirements-dev.txt

@@ -0,0 +1,6 @@
+# Development and linting dependencies only.
+# The bot-bottle project itself has no runtime dependencies.
+# These tools are used for code quality checks in CI/CD.
+
+pylint>=3.0.0
+pyright>=1.1.300