Remove something I don't remember why I've added

.docker/lint/c-lint.Dockerfile

@@ -1,7 +1,6 @@
 FROM python:3
 
-SHELL ["/bin/bash", "-o", "pipefail", "-c"]
-
+RUN pip install -U pip
 RUN pip install cpplint
 RUN apt update && apt install clang-format -y