compiletest: Don't look for Dylib if no-prefer-dynamic

Since it does not make sense to do so. If someone prefers no dynamic
linking, it is much more likely that they want to link with a Lib
instead.

Author: Enselic

src/tools/compiletest/src/runtest.rs

@@ -1427,7 +1427,7 @@ impl<'test> TestCx<'test> {
         } else if aux_type.is_some() {
             panic!("aux_type {aux_type:?} not expected");
         } else if aux_props.no_prefer_dynamic {
-            (AuxType::Dylib, None)
+            (AuxType::Lib, None)
         } else if self.config.target.contains("emscripten")
             || (self.config.target.contains("musl")
                 && !aux_props.force_host