deps: update bitfield-struct and open-enum (#60)

Update these dependencies to the latest versions from crates.io:
- bitfield-struct to 0.6.2
- open-enum to 0.5.1

This helps reduce duplicates due to different crate versions in the
dependency
trees of consuming projects (for example Coconut-SVSM).

---------

Signed-off-by: Oliver Steffen <[email protected]>
Co-authored-by: Chris Oo <[email protected]>

Cargo.toml

@@ -13,10 +13,10 @@ igvm_defs = { path = "igvm_defs", version = "0.3.1" }
 igvm = { path = "igvm", version = "0.3.1" }
 
 anyhow = "1.0"
-bitfield-struct = "0.5"
+bitfield-struct = "0.6.2"
 crc32fast = { version = "1.3.2", default-features = false }
 hex = { version = "0.4", default-features = false }
-open-enum = "0.4.1"
+open-enum = "0.5.1"
 range_map_vec = "0.2.0"
 static_assertions = "1.1"
 thiserror = "1.0"