Ignore pip cache in docker build

[santuari]

Description

The pip cache is created during the Docker build and it might occupy around 50MB. The cache is not needed for running the application.

Motivation and Context

Reduce the size of the Docker image

How Has This Been Tested?

I tested by pushing the same function with and without the cache. I also expect that this cannot impact the function behavior.

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Version change (see: Impact to existing users)

Impact to existing users

Checklist:

• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [x] I've read the CONTRIBUTION guide
• [x] I have signed-off my commits with git commit -s
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.

[derek[bot]]

Thank you for your contribution. I've just checked and your commit doesn't appear to be signed-off. That's something we need before your Pull Request can be merged. Please see our contributing guide. Tip: if you only have one commit so far then run: git commit --amend --signoff and then git push --force.

[santuari]

Hi all,

I have created this PR that it is very simple. and I guess that no tests are needed. Should I do something more?

[santuari]

Any news on this?