Fix release_head_macos and release_head_linux jobs after upgrading xcode base image on CircleCI

[camillof]

release_head_macos

• After upgrading the XCode version on our macos_image for CircleCI jobs on Fix CI xcode_install_go script #498 , the pip version was also upgraded, so we should use pip3 instead of pip.

Failed job: https://app.circleci.com/pipelines/github/codeclimate/test-reporter/144/workflows/88253465-f0e4-4fdd-8232-4d51b61d03a4/jobs/1225
CircleCi image manifest: https://circle-macos-docs.s3.amazonaws.com/image-manifest/v3587/index.html

release_head_linux

• Linux repository was pointing to a non-existing package, causing the job to fail. Running apt-get update fixes the issue.

http://deb.debian.org/debian/pool/main/p/pillow/python3-pil_5.4.1-2+deb10u2_amd64.deb # Before
http://deb.debian.org/debian/pool/main/p/pillow/python3-pil_5.4.1-2+deb10u3_amd64.deb  # After

Reference: http://deb.debian.org/debian/pool/main/p/pillow/

Failed job: https://app.circleci.com/pipelines/github/codeclimate/test-reporter/144/workflows/88253465-f0e4-4fdd-8232-4d51b61d03a4/jobs/1226