feat(RELEASE-1102): remove unused data.fbc params

this commit removes iibServiceConfigSecret  and iibOverwriteFromIndexCredential
as both are paremeters pinned by the FBC pipeline and should not be rewritten.

tests/release/pipelines/fbc_release.go

@@ -294,8 +294,6 @@ func createFBCReleasePlanAdmission(fbcRPAName string, managedFw framework.Framew
 			"targetIndex":                     constants.TargetIndex,
 			"binaryImage":                     constants.BinaryImage,
 			"publishingCredentials":           "fbc-preview-publishing-credentials",
-			"iibServiceConfigSecret":          "iib-preview-services-config",
-			"iibOverwriteFromIndexCredential": "iib-overwrite-fromimage-credentials",
 			"requestUpdateTimeout":            "1500",
 			"buildTimeoutSeconds":             "1500",
 			"hotfix":                          hotfix,