These are some changes that reduce the image size and make the build faster

dnf:
--nodocs doesn't install documentation files, can be be checked with e.g rpm -qd unzip

Using install_weak_deps=0 installs about 110 less packages, can be checked with dnf install

clean all will remove package install cache, I also added in a rm -rf for the "best practices"

pip:
--no-cache-dir kinda self-explanatory

-U will upgrade the package if there's a new release

Overall the difference in the image size is 2.58GB without, versus 2.06GB with the new flags

I also corrected this => WARN: FromAsCasing: 'as' and 'FROM' keywords' casing do not match (line 1)

Of course I ran a basic test to make sure that it still works

curl 'http://localhost:9000/2015-03-31/functions/function/invocations' -d '{}'
"Example Domain\nThis domain is for use in illustrative examples in documents. You may use this domain in literature without prior coordination or asking for permission.\nMore information..."