Support PyO3 0.20.x

Author: musicinmybrain

rust/Cargo.toml

@@ -14,7 +14,7 @@ strip = true
 overflow-checks = false
 
 [dependencies]
-pyo3 = { version = "0.19.0", features = ["extension-module", "generate-import-lib"] }
+pyo3 = { version = ">= 0.19, < 0.21", features = ["extension-module", "generate-import-lib"] }
 mimalloc = { version = "0.1.39", optional = true, default-features = false }
 
 [features]