[ci] Enable flake8 linting for Python code in util
This isn't as "canonical" as running yapf, but at least the results
shouldn't depend on Python version. The end result is that we run
flake8 on each Python file touched by the change.
Signed-off-by: Rupert Swarbrick <rswarbrick@lowrisc.org>
diff --git a/apt-requirements.txt b/apt-requirements.txt
index afb46e8..5a666e9 100644
--- a/apt-requirements.txt
+++ b/apt-requirements.txt
@@ -8,6 +8,7 @@
build-essential
clang-format
curl
+flake8
flex
g++
git
