chore(agent-data-plane): bump release version to 1.2.1 (#1871)

Author: thieman

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "agent-data-plane"
-version = "1.2.0"
+version = "1.2.1"
 edition = { workspace = true }
 license = { workspace = true }
 repository = { workspace = true }