Bump sha2 from 0.9.3 to 0.9.4

Bumps [sha2](https://github.com/RustCrypto/hashes) from 0.9.3 to 0.9.4.
- [Release notes](https://github.com/RustCrypto/hashes/releases)
- [Commits](https://github.com/RustCrypto/hashes/compare/sha2-v0.9.3...sha2-v0.9.4)

Signed-off-by: dependabot[bot] <support@github.com>

Cargo.lock

@@ -680,6 +680,12 @@ version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "245097e9a4535ee1e3e3931fcfcd55a796a44c643e8596ff6566d68f09b87bbc"
 
+[[package]]
+name = "cpufeatures"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5cd5a7748210e7ec1a9696610b1015e6e31fbf58f77a160801f124bd1c36592a"
+
 [[package]]
 name = "cpuid-bool"
 version = "0.1.2"
@@ -937,7 +943,7 @@ dependencies = [
  "ed25519",
  "rand 0.7.3",
  "serde",
- "sha2 0.9.3",
+ "sha2 0.9.4",
  "zeroize",
 ]
 
@@ -1783,7 +1789,7 @@ dependencies = [
  "rand 0.7.3",
  "ring",
  "rw-stream-sink",
- "sha2 0.9.3",
+ "sha2 0.9.4",
  "smallvec",
  "thiserror",
  "unsigned-varint 0.7.0",
@@ -1837,7 +1843,7 @@ dependencies = [
  "prost",
  "prost-build",
  "rand 0.7.3",
- "sha2 0.9.3",
+ "sha2 0.9.4",
  "snow",
  "static_assertions",
  "x25519-dalek",
@@ -2238,7 +2244,7 @@ dependencies = [
  "digest 0.9.0",
  "generic-array 0.14.4",
  "multihash-derive",
- "sha2 0.9.3",
+ "sha2 0.9.4",
  "unsigned-varint 0.5.1",
 ]
 
@@ -3417,13 +3423,13 @@ dependencies = [
 
 [[package]]
 name = "sha2"
-version = "0.9.3"
+version = "0.9.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fa827a14b29ab7f44778d14a88d3cb76e949c45083f7dbfa507d0cb699dc12de"
+checksum = "d8f6b75b17576b792bef0db1bcc4b8b8bcdf9506744cf34b974195487af6cff2"
 dependencies = [
  "block-buffer 0.9.0",
  "cfg-if 1.0.0",
- "cpuid-bool 0.1.2",
+ "cpufeatures",
  "digest 0.9.0",
  "opaque-debug 0.3.0",
 ]
@@ -3519,7 +3525,7 @@ dependencies = [
  "rand_core 0.5.1",
  "ring",
  "rustc_version",
- "sha2 0.9.3",
+ "sha2 0.9.4",
  "subtle 2.4.0",
  "x25519-dalek",
 ]
@@ -3769,7 +3775,7 @@ dependencies = [
  "serde",
  "serde_cbor",
  "serde_json",
- "sha2 0.9.3",
+ "sha2 0.9.4",
  "sigma_fun",
  "sled",
  "spectral",
@@ -3878,7 +3884,7 @@ dependencies = [
  "rand 0.7.3",
  "serde",
  "serde_json",
- "sha2 0.9.3",
+ "sha2 0.9.4",
 ]
 
 [[package]]
@@ -3893,7 +3899,7 @@ dependencies = [
  "rand 0.8.3",
  "serde",
  "serde_json",
- "sha2 0.9.3",
+ "sha2 0.9.4",
 ]
 
 [[package]]