Update to sha2-0.11

This version dropped the ability to format hashes as hex, so add a
dependency on base16ct to take care of that as recommended here:
RustCrypto/hybrid-array#201 (comment)

Author: nicholasbishop

Cargo.lock

@@ -9,8 +9,9 @@ repository = "https://github.com/rust-osdev/ovmf-prebuilt"
 description = "Library to download and cache OVMF prebuilt binaries"
 
 [dependencies]
+base16ct = "1.0.0"
 log = "0.4"
 lzma-rs = "0.3"
-sha2 = "0.10"
+sha2 = "0.11"
 tar = "0.4"
 ureq.workspace = true

ovmf-prebuilt/Cargo.toml

@@ -1,4 +1,5 @@
 use crate::{Error, Source};
+use base16ct::HexDisplay;
 use log::info;
 use sha2::{Digest, Sha256};
 use std::io::{self, Cursor, Read};
@@ -38,7 +39,7 @@ pub(crate) fn update_cache(source: Source, prebuilt_dir: &Path) -> Result<(), Er
     let data = retry(MAX_DOWNLOAD_RETRIES, || download_url(&url))?;
 
     // Validate the hash.
-    let actual_hash = format!("{:x}", Sha256::digest(&data));
+    let actual_hash = format!("{:x}", HexDisplay(&Sha256::digest(&data)));
     if actual_hash != source.sha256 {
         return Err(Error::HashMismatch {
             actual: actual_hash,