create mypy cache dir if it doesn't exist (#14579)

### Description

When running `make lint` multiple times, i can see the error `mkdir:
.mypy_cache: File exists`. Use `mkdir -p` to solve this problem.
<img width="1512" alt="Screenshot 2023-12-12 at 11 22 01 AM"
src="https://github.com/langchain-ai/langchain/assets/10000925/1429383d-3283-4e22-8882-5693bc50b502">

libs/community/Makefile

@@ -41,7 +41,7 @@ lint lint_diff lint_package lint_tests:
 	poetry run ruff .
 	[ "$(PYTHON_FILES)" = "" ] || poetry run ruff format $(PYTHON_FILES) --diff
 	[ "$(PYTHON_FILES)" = "" ] || poetry run ruff --select I $(PYTHON_FILES)
-	[ "$(PYTHON_FILES)" = "" ] || mkdir $(MYPY_CACHE) || poetry run mypy $(PYTHON_FILES) --cache-dir $(MYPY_CACHE)
+	[ "$(PYTHON_FILES)" = "" ] || mkdir -p $(MYPY_CACHE) || poetry run mypy $(PYTHON_FILES) --cache-dir $(MYPY_CACHE)
 
 format format_diff:
 	poetry run ruff format $(PYTHON_FILES)

libs/experimental/Makefile

@@ -42,7 +42,7 @@ lint lint_diff lint_package lint_tests:
 	poetry run ruff .
 	poetry run ruff format $(PYTHON_FILES) --diff
 	poetry run ruff --select I $(PYTHON_FILES)
-	mkdir $(MYPY_CACHE); poetry run mypy $(PYTHON_FILES) --cache-dir $(MYPY_CACHE)
+	mkdir -p $(MYPY_CACHE); poetry run mypy $(PYTHON_FILES) --cache-dir $(MYPY_CACHE)
 
 format format_diff:
 	poetry run ruff format $(PYTHON_FILES)