mypy: don't ignore all imports, also disallow implicit optional (#8814)

* mypy: don't ignore all imports

* mypy: disallow implicit_optional

pyproject.toml

@@ -112,6 +112,10 @@ tests = [
     "types-requests",
     "types-tabulate",
     "types-toml",
+    "types-appdirs",
+    "types-colorama",
+    "types-psutil",
+    "types-tqdm",
 ]
 all = ["dvc[azure,gdrive,gs,hdfs,oss,s3,ssh,webdav,webhdfs]"]
 dev = ["dvc[azure,gdrive,gs,hdfs,oss,s3,ssh,webdav,webhdfs,tests]"]
@@ -221,16 +225,50 @@ show_error_codes = true
 show_error_context = true
 show_traceback = true
 pretty = true
-# See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports.
-ignore_missing_imports = true
-implicit_optional = true
+no_implicit_optional = true
 check_untyped_defs = false
+strict_equality = true
+strict_concatenate = true
 # Warnings
 warn_no_return = true
 warn_redundant_casts = true
+warn_unused_configs = true
 warn_unreachable = true
 files = ["dvc"]
 
+[[tool.mypy.overrides]]
+module = [
+    "celery.*",
+    "configobj.*",
+    "dpath.*",
+    "dvc_data.*",
+    "dvc_http.*",
+    "dvc_objects.*",
+    "dvc_render.*",
+    "dvc_ssh",
+    "dvc_studio_client.*",
+    "dvc_task.*",
+    "flatten_dict",
+    "fsspec.*",
+    "funcy.*",  # https://github.com/Suor/funcy/issues/106,
+    "grandalf.*",
+    "ipdb",
+    "iterative_telemetry",
+    "kombu.*",
+    "networkx.*",  # https://github.com/networkx/networkx/issues/3988
+    "pygtrie.*",
+    "pyinstrument",
+    "pytest_docker.plugin",
+    "ruamel.yaml.*",
+    "scmrepo.*",
+    "tpi.*",
+    "viztracer",
+    "voluptuous",
+    "yappi",
+    "zc.*",
+]
+ignore_missing_imports = true
+
 [tool.pylint.master]
 extension-pkg-whitelist = ["pygit2"]
 init-hook = "import sys; sys.path.append(str('tests'))"