Pin python<3.12 in hooks to install dependencies

Some libraries are only supported for python <= 3.12 this sets the
python version to 3.12 for the docs and validate_examples hooks so that
Ray gets installed.

.github/workflows/docs.yml

diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index b6777ed..e64ad45 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -23,6 +23,8 @@
     steps:
       - uses: actions/checkout@v3
       - uses: actions/setup-python@v3
+        with:
+          python-version: '3.12'
       - name: Install dependencies
         run: |
           pip install -e ".[documentation]"

.github/workflows/python-package.yml

diff --git a/.github/workflows/python-package.yml b/.github/workflows/python-package.yml
index 3dec66a..a8b85d0 100644
--- a/.github/workflows/python-package.yml
+++ b/.github/workflows/python-package.yml
@@ -52,6 +52,8 @@
     steps:
       - uses: actions/checkout@v3
       - uses: actions/setup-python@v3
+        with:
+          python-version: '3.12'
       - name: Install dependencies
         run: |
           python -m pip install -e ".[tests]"