Docker build fails on ln -s on m1 mac

[geoff-va]

M1 Mac w/ Mac OS 11.5.1

Docker Desktop: 4.0.0
Docker Engine: 20.10.8
Docker Compose: v2.0.0-rc.2

When running make docker_build, the build fails with the following message:

 => ERROR [5/6] RUN ln -s /usr/bin/python3.8 /usr/bin/python &&     /usr/bin/python3 -m pip install --upgrade pip &&     pip install -r /usr/local/src/xblock-sdk/requi  0.2s
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 > [5/6] RUN ln -s /usr/bin/python3.8 /usr/bin/python &&     /usr/bin/python3 -m pip install --upgrade pip &&     pip install -r /usr/local/src/xblock-sdk/requirements/dev.txt:
#9 0.174 /usr/bin/ln: failed to create symbolic link '/usr/bin/python': File exists

Seemed to resolve by having it first remove the link then recreate it by using ln -s -f