Remove pyenv install (#1851)

Author: yongtang

.github/workflows/build.yml

@@ -147,9 +147,6 @@ jobs:
           set -x -e
           pyenv versions
           pyenv install --list
-          pyenv install 3.7
-          pyenv install 3.8
-          pyenv install 3.9
           # pyenv install ${{ matrix.python }}
           pyenv local ${{ matrix.python }}
           pyenv versions