docs: document how to configure OS cert store for Python (#22299)

docs/usage/examples/self-hosting.md

@@ -437,6 +437,14 @@ RUN update-ca-certificates
 # Change back to the Ubuntu user
 USER 1000
 
-# Node comes with an own certificate authority store and thus needs to trust the self-signed certificate explicitly
+# Some tools come with their own certificate authority stores and thus need to trust the self-signed certificate or the entire OS store explicitly.
+# This list is _not_ comprehensive and other tools may require further configuration.
+#
+# Node
 ENV NODE_EXTRA_CA_CERTS=/usr/local/share/ca-certificates/self-signed-certificate.crt
+# Python
+RUN pip config set global.cert /etc/ssl/certs/ca-certificates.crt
+ENV REQUESTS_CA_BUNDLE=/etc/ssl/certs/ca-certificates.crt
+# OpenSSL
+ENV SSL_CERT_FILE=/etc/ssl/certs/ca-certificates.crt
 ```