Fix readthedocs fail test changing build.image into build.os (#487)

* Empty commit

* Change deprecated build.image into build.os in the file .readthedocs.yml

* Specify ubuntu version

* Fix method to specify python version

* Fix method to specify path

* Fix method to specify path

.readthedocs.yml

@@ -5,6 +5,12 @@
 # Required
 version: 2
 
+# Set the OS, Python version and other tools you might need
+build:
+  os: ubuntu-22.04
+  tools:
+    python: "3.8"
+
 # Build documentation in the docs/ directory with Sphinx
 sphinx:
   configuration: docs/conf.py
@@ -16,13 +22,11 @@ sphinx:
 # Optionally build your docs in additional formats such as PDF and ePub
 formats: all
 
-# Optionally set the version of Python and requirements required to build your docs
+# Optional but recommended, declare the Python requirements required
+# to build your documentation
+# See https://docs.readthedocs.io/en/stable/guides/reproducible-builds.html
 python:
-  version: 3.8
   install:
-    - requirements: docs/requirements_rtd.txt
-    - method: setuptools
-      path: .
-
-build:
-  image: latest  # See: https://hub.docker.com/r/readthedocs/build/
+  - requirements: docs/requirements_rtd.txt
+  - method: setuptools
+    path: .