问题原因：

Error: Invalid formula: /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/Formula/openjdk.rb

openjdk: undefined local variable or method `version' for #<Livecheck:0x00007f81c3905190>

Error: Invalid formula: /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/Formula/python@3.9.rb

python@3.9: undefined method `on_macos' for #<PourBottleCheck:0x00007f81cd5b0968>

Error: Cannot tap homebrew/core: invalid syntax in tap!

Error: Failure while executing; `/usr/local/bin/brew tap homebrew/core` exited with 1.

解决方案：

cd /usr/local/Homebrew/Library/Taps/mkdir homebrewcd homebrew

git clone https://mirrors.ustc.edu.cn/homebrew-core.git

brew update

brew update