Virtual-environments: Updating Brew fails on macos-latest

[mcmarkj]

Description
Installation or Upgrading of Homebrew on macos-latest fails with a critical error

Error: Fetching /usr/local/Homebrew/Library/Taps/local/homebrew-openssl failed!
Fetching /usr/local/Homebrew/Library/Taps/local/homebrew-python2 failed!
...
Failed during: /usr/local/bin/brew update --force
Error: Process completed with exit code 1.

This doesn't happen if I use the macos-11, where it updates as expected. We run this step before we checkout any code from our repo. Hence why I believe this to be an issue with the environment.

Area for Triage: Packages

Question, Bug, or Feature?: Bug

Virtual environments affected

• [X] macOS 10.15
• [ ] Ubuntu 16.04 LTS
• [ ] Ubuntu 18.04 LTS
• [ ] Ubuntu 20.04 LTS
• [ ] Windows Server 2016 R2
• [ ] Windows Server 2019

Expected behavior
Homebrew should update correctly and continue with a 0 exit code.

Actual behavior
Homebrew unable to update, installing old versions of packages.

Repro steps

1. Run brew update
   or
2. Install homebrew again

[al-cheb]

Hello, @majorvin
Duplicate https://github.com/actions/virtual-environments/issues/1811 ,as a temporary workaround - https://github.com/actions/virtual-environments/issues/1811#issuecomment-708480190