chore: checkpoint before Python removal

vendor/tiny-keccak/build.rs

@@ -0,0 +1,22 @@
+#[cfg(not(any(
+    feature = "keccak",
+    feature = "shake",
+    feature = "sha3",
+    feature = "cshake",
+    feature = "kmac",
+    feature = "tuple_hash",
+    feature = "parallel_hash",
+    feature = "k12",
+    feature = "fips202",
+    feature = "sp800"
+)))]
+compile_error!(
+    "You need to specify at least one hash function you intend to use. \
+    Available options:\n\
+    keccak, shake, sha3, cshake, kmac, tuple_hash, parallel_hash, k12, fips202, sp800\n\
+    e.g.\n\
+    tiny-keccak = { version = \"2.0.0\", features = [\"sha3\"] }"
+);
+
+fn main() {
+}