Stronger WASM compression (#9875)

Use strongest compression 22 instead of just 3. See
[docs](https://docs.rs/zstd/0.13.3/zstd/stream/write/struct.Encoder.html#method.new).
Reduces our KAH compressed size by 25%.

Build time by compression level:

| Compression | Build Time | Size    | Decomp Time |
  |-------------|-----------|---------|-------------|
  | 3           | 5:54      | 3192172 | 0.013039s   |
  | 10          | 5:58      | 2716940 | 0.011962s   |
  | 22          | 6:06      | 2387562 | 0.013745s   |

---------

Signed-off-by: Oliver Tale-Yazdi <[email protected]>

Author: ggwpez

prdoc/pr_9875.prdoc

@@ -0,0 +1,9 @@
+title: Stronger WASM compression
+doc:
+- audience: Runtime Dev
+  description: |-
+    Use strongest compression 22 instead of just 3. See [docs](https://docs.rs/zstd/0.13.3/zstd/stream/write/struct.Encoder.html#method.new).
+    Reduces our KAH compressed size by 25%.
+crates:
+- name: sp-maybe-compressed-blob
+  bump: patch

substrate/primitives/maybe-compressed-blob/src/lib.rs

@@ -91,7 +91,7 @@ pub fn compress(blob: &[u8], bomb_limit: usize) -> Option<Vec<u8>> {
 	let mut buf = ZSTD_PREFIX.to_vec();
 
 	{
-		let mut v = zstd::Encoder::new(&mut buf, 3).ok()?.auto_finish();
+		let mut v = zstd::Encoder::new(&mut buf, 22).ok()?.auto_finish();
 		v.write_all(blob).ok()?;
 	}