update version of identity model libraries (#49349)

Co-authored-by: Keegan Caruso <[email protected]>

Author: keegan-caruso

eng/Versions.props

@@ -11,7 +11,7 @@
     <AspNetCorePatchVersion>0</AspNetCorePatchVersion>
     <PreReleaseVersionIteration>7</PreReleaseVersionIteration>
     <ValidateBaseline>true</ValidateBaseline>
-    <IdentityModelVersion>6.31.0</IdentityModelVersion>
+    <IdentityModelVersion>7.0.0-preview</IdentityModelVersion>
     <!--
         When StabilizePackageVersion is set to 'true', this branch will produce stable outputs for 'Shipping' packages
     -->