Remove deprecated bdk-ffi-bindgen tool

Cargo.toml

@@ -1,6 +1,6 @@
 [workspace]
-members = ["bdk-ffi", "bdk-ffi-bindgen"]
-default-members = ["bdk-ffi", "bdk-ffi-bindgen"]
+members = ["bdk-ffi"]
+default-members = ["bdk-ffi"]
 exclude = ["api-docs", "bdk-android", "bdk-jvm", "bdk-python", "bdk-swift"]
 
 [profile.release-smaller]
@@ -9,4 +9,4 @@ opt-level = 'z'     # Optimize for size.
 lto = true          # Enable Link Time Optimization
 codegen-units = 1   # Reduce number of codegen units to increase optimizations.
 panic = 'abort'     # Abort on panic
-strip = true        # Strip symbols from binary*
+strip = true        # Strip symbols from binary*