Enable Microsoft Fabric S3 connections with custom OIDC providers (Okta)

[ashish-negi]

Please extend the current Entra-based OIDC integration for Amazon S3 shortcuts to support any standards-compliant OIDC issuer. This would allow enterprises who use Okta (or other IdPs) to federate directly to AWS IAM via OIDC and obtain short-lived STS credentials—without managing long-lived keys or duplicating identities in Entra.
Why: Improves security (short-term creds), reduces operational overhead, and aligns Fabric with multicloud identity realities.
How (high-level):

• Add connection auth kind “OIDC (Custom Provider)” with fields for issuer discovery URL, client ID/secret, audience (default sts.amazonaws.com), scopes, RoleArn.
• Validate tokens via JWKS, verify iss/aud/exp, then call AssumeRoleWithWebIdentity to get access_key/secret_key/sessionToken.
• Support private S3 endpoints via on-premises data gateway.