Add explicit zeroize features (#539)

argon2/Cargo.toml

@@ -38,6 +38,7 @@ std = ["alloc", "password-hash?/std"]
 
 rand = ["password-hash?/rand_core"]
 simple = ["password-hash"]
+zeroize = ["dep:zeroize"]
 
 [lints.rust.unexpected_cfgs]
 level = "warn"

balloon-hash/Cargo.toml

@@ -32,6 +32,7 @@ alloc = ["password-hash/alloc"]
 parallel = ["rayon", "std"]
 rand = ["password-hash/rand_core"]
 std = ["alloc", "password-hash/std"]
+zeroize = ["dep:zeroize"]
 
 [package.metadata.docs.rs]
 all-features = true

bcrypt-pbkdf/Cargo.toml

@@ -26,3 +26,4 @@ hex-literal = "0.4.0"
 default = ["alloc", "std"]
 alloc = []
 std = []
+zeroize = ["dep:zeroize"]