Update the docs to use assertingparty instead of identityprovider to close #12810#17081

jzheaux merged 2 commits intospring-projects:6.3.xspring-projects/spring-security:6.3.xfrom

danilopiazza:issue-12810-saml2-docs-identityprovider-vs-assertingpartydanilopiazza/spring-security:issue-12810-saml2-docs-identityprovider-vs-assertingpartyCopy head branch name to clipboard