Pull in Provider impl from anyhow 1.0.65

Cargo.toml

@@ -16,7 +16,7 @@ rust-version = "1.31"
 thiserror-impl = { version = "=1.0.34", path = "impl" }
 
 [dev-dependencies]
-anyhow = "1.0.64"
+anyhow = "1.0.65"
 ref-cast = "1.0"
 rustversion = "1.0"
 trybuild = { version = "1.0.49", features = ["diff"] }

tests/test_backtrace.rs

@@ -140,8 +140,7 @@ pub mod structs {
         let error = AnyhowBacktrace {
             source: anyhow::Error::msg("..."),
         };
-        // FIXME: change back to is_some after `impl Provider for anyhow::Error` exists.
-        assert!(any::request_ref::<Backtrace>(&error).is_none());
+        assert!(any::request_ref::<Backtrace>(&error).is_some());
 
         let error = BoxDynErrorBacktrace {
             source: Box::new(PlainBacktrace {