test: improve performance for property tests

Set the opt-level to 3 as suggested by the proptest book.

Reference:
- https://proptest-rs.github.io/proptest/proptest/tips-and-best-practices.html#setting-opt-level

Cargo.toml

@@ -67,5 +67,11 @@ inherits = "release"
 opt-level = "s"
 lto = true
 
+[profile.test.package.proptest]
+opt-level = 3
+
+[profile.test.package.rand_chacha]
+opt-level = 3
+
 [patch.crates-io]
 softbuffer = { git = "https://github.com/CBenoit/softbuffer.git", rev = "8a9e7f95e054f9af5752682aa5f27890aeb1b094" }