Update mambaforge and remove external links in documentation site

.readthedocs.yml

@@ -11,9 +11,9 @@ sphinx:
 
 # Use mamba to reduce the memory consumption of the dependency solving process.
 build:
-  os: "ubuntu-20.04"
+  os: "ubuntu-22.04"
   tools:
-    python: "mambaforge-4.10"
+    python: "mambaforge-22.9"
 
 # Conda environment
 conda:

docs/source/conf.py

@@ -71,16 +71,6 @@ def _get_project_meta():
 # html_theme = 'sphinx_rtd_theme'
 html_theme = "pydata_sphinx_theme"
 
-# Theme options are theme-specific and customize the look and feel of a theme
-# further.  For a list of options available for each theme, see the
-# documentation.
-html_theme_options = {
-    "external_links": [
-        {"name": "github_url", "url": "https://github.com/munterfi/glacier-flow-model"},
-        {"name": "twitter_url", "url": "https://twitter.com/munterfi1"},
-    ]
-}
-
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".