Remove rtd (#2478)

.readthedocs.yaml

@@ -1,37 +0,0 @@
-# .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-20.04
-  tools:
-    python: '3.9'
-    # You can also specify other tool versions:
-    # nodejs: "16"
-    # rust: "1.55"
-    # golang: "1.17"
-
-# Build documentation in the docs/ directory with Sphinx
-sphinx:
-  fail_on_warning: true
-  configuration: docs/conf.py
-
-# If using Sphinx, optionally build your docs in additional formats such as PDF
-# formats:
-#    - pdf
-
-# Optionally declare the Python requirements required to build your docs
-python:
-  install:
-    # Equivalent to 'pip install .'
-    - method: pip
-      path: .
-    # Equivalent to 'pip install .[docs]'
-    - method: pip
-      path: .
-      extra_requirements:
-        - docs