chore: Remove python playground

Author: Tomasz Kulik

Cargo.toml

@@ -1,6 +1,6 @@
 [workspace]
 members = ["packages/*"]
-exclude = ["contracts", "packages/cw-schema-codegen/playground"]
+exclude = ["contracts"]
 
 # Resolver has to be set explicitly in workspaces
 # due to https://github.com/rust-lang/cargo/issues/9956