Update check/mypy to remove explicit mypy.ini argument

Now that the options are in pyproject.toml, the explicit argument is no
longer necessary.

Author: mhucka

check/mypy

@@ -14,7 +14,7 @@
 # limitations under the License.
 
 ################################################################################
-# Runs mypy on the repository using a preconfigured mypy.ini file.
+# Runs mypy on the repository starting from the root.
 #
 # Usage:
 #     check/mypy [--flags]
@@ -25,7 +25,7 @@ cd "$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )" || exit 1
 cd "$(git rev-parse --show-toplevel)" || exit 1
 
 echo -e -n "\033[31m"
-mypy --config-file=dev_tools/conf/mypy.ini "$@" .
+mypy "$@" .
 result=$?
 echo -e -n "\033[0m"