chore: update documentation URLs to use workspace setting

Replace all docs.rs documentation URLs with documentation.workspace = true
to inherit from the workspace's docs.pezkuwichain.io URL.

pezcumulus/test/runtime/Cargo.toml

@@ -5,7 +5,7 @@ authors.workspace = true
 edition.workspace = true
 publish = false
 description = "Pezkuwi SDK cumulus/teyrchain component: test runtime"
-documentation = "https://docs.rs/pezcumulus-test-runtime"
+documentation.workspace = true
 repository = { workspace = true }
 homepage = { workspace = true }
 license = { workspace = true }