Add RTD configuration file which is now required

.readthedocs.yaml

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+# .readthedocs.yaml
+# Read the Docs configuration file
+# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
+
+# Required
+version: 2
+
+# Set the version of Python and other tools you might need
+build:
+  os: ubuntu-22.04
+  tools:
+    python: "3.12"
+
+# Build documentation in the docs/api directory with Sphinx
+sphinx:
+  configuration: docs/api/conf.py
+  fail_on_warning: true
+
+# Build docs in additional formats such as PDF and ePub
+formats: all
+
+# Specify dependencies to enable reproducible builds:
+# https://docs.readthedocs.io/en/stable/guides/reproducible-builds.html
+python:
+  install:
+    - requirements: packaging/pip_requirements_minimal.txt
+    - method: pip
+      path: ./packaging/

packaging/pip_requirements_minimal.txt

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+# minimal
+Pillow==9.3.0; python_version >= '3.7' and python_version < '3.12'
+Pillow==10.3.0; python_version >= '3.12'