Update hadolint to 2.1.0 (#11)

Update hadolint to 2.1.0

Co-authored-by: cl0ne <cl0ne@mithril.org.ua>
Reviewed-on: https://code.nix.org.ua/NiX/docker-linter/pulls/11
Co-Authored-By: Vladislav Glinsky <cl0ne@no-reply.code.nix.org.ua>
Co-Committed-By: Vladislav Glinsky <cl0ne@no-reply.code.nix.org.ua>

Dockerfile

@@ -4,7 +4,7 @@ LABEL maintainer="sev@nix.org.ua"
 
 ENV SHELLCHECK_VER=0.7.1 \
     YAMLLINT_VER=1.26.0 \
-    HADOLINT_VER=1.19.0 \
+    HADOLINT_VER=2.1.0 \
     PYLINT_VER=2.7.2 \
     ANSIBLE_LINT=4.3.7