page-tracking: Remove static lifetime on DeRef in PageBox

See: rust-lang/rust#105572
Trait implementations adding more restrictive constrains to a trait
definition will soon be an error.

Luckily, it doesn't seem that this 'static lifetime bound is needed by
`PageBox` so remove it to make newer versions of rust happy.

Signed-off-by: Dylan Reid <dgreid@rivosinc.com>

page-tracking/src/collections/page_box.rs

@@ -277,7 +277,7 @@ impl<T> Clone for StaticPageRef<T> {
 impl<T> Deref for StaticPageRef<T> {
     type Target = T;
 
-    fn deref(&self) -> &'static T {
+    fn deref(&self) -> &T {
         // Safe because this pointer is guaranteed to be valid in the constructor.
         unsafe { self.0.as_ref() }
     }