lock mypy

Author: juliannguyen4

.github/workflows/tests.yml

@@ -214,7 +214,8 @@ jobs:
     - name: Install client
       run: pip install *.whl
 
-    - run: pip install mypy
+    - run: pip install -r requirements.txt
+      working-directory: .github/workflows
 
     - run: stubtest aerospike --allowlist stubtest-allowlist