bin/pyenv update

.github/workflows/ubuntu_tests.yml

@@ -22,6 +22,8 @@ jobs:
           sudo apt-get install -y build-essential libssl-dev zlib1g-dev libbz2-dev \
               libreadline-dev libsqlite3-dev wget curl llvm libncurses5-dev libncursesw5-dev \
               xz-utils tk-dev libffi-dev liblzma-dev python-openssl git
+      - run: git clone https://github.com/pyenv/pyenv-update.git $(pyenv root)/plugins/pyenv-update
+      - run: bin/pyenv update
       - run: bin/pyenv install ${{ matrix.python-version }}
       - run: bin/pyenv global ${{ matrix.python-version }}
       - run: bin/pyenv rehash