DOCSP-40566 - Sync OIDC (#95)

(cherry picked from commit 00d177d)

Author: mongoKart

source/security/enterprise-authentication.txt

@@ -215,6 +215,11 @@ For more information about the MONGODB-OIDC authentication mechanism, see
 :manual:`MongoDB Server Parameters </reference/parameters/#mongodb-parameter-param.oidcIdentityProviders>`
 in the {+mdb-server+} manual.
 
+.. note:: 
+
+   Because Python's Standard Library doesn't support asynchronous HTTP requests,
+   all OIDC requests from {+driver-short+} are synchronous and block the ``asyncio`` loop.
+
 .. _pymongo-mongodb-oidc-azure-imds:
 
 Azure IMDS