chore: silence fatcontext on the deliberate per-level context nesting in the depth test

Signed-off-by: AkramBitar <akram@il.ibm.com>

Author: AkramBitar

token/driver/identity_nesting_test.go

@@ -26,6 +26,9 @@ func TestEnterCompositeIdentity_UnseededContextUsesDefaults(t *testing.T) {
 	for i := range maxDepth {
 		next, err := EnterCompositeIdentity(ctx)
 		require.NoError(t, err, "descent to depth %d should be allowed", i+1)
+		//nolint:fatcontext // deriving one context per level is the mechanism under test: each
+		// iteration stands in for one step down a nested composite identity, which is exactly how
+		// the deserializers descend.
 		ctx = next
 	}