[mypy] Enable following imports for some directories (#6681)

pyproject.toml

@@ -48,9 +48,23 @@ python_version = "3.8"
 
 ignore_missing_imports = true
 check_untyped_defs = true
-follow_imports = "skip"
+follow_imports = "silent"
 
-files = "vllm"
+# After fixing type errors resulting from follow_imports: "skip" -> "silent",
+# move the directory here and remove it from format.sh and mypy.yaml
+files = [
+    "vllm/*.py",
+    "vllm/adapter_commons",
+    "vllm/assets",
+    "vllm/inputs",
+    "vllm/logging",
+    "vllm/multimodal",
+    "vllm/platforms",
+    "vllm/server",
+    "vllm/transformers_utils",
+    "vllm/triton_utils",
+    "vllm/usage",
+]
 # TODO(woosuk): Include the code from Megatron and HuggingFace.
 exclude = [
     "vllm/model_executor/parallel_utils/|vllm/model_executor/models/",