chore: remove temporary .cargo/config.toml used during cargo-stylus investigation

The symbolic link solution (ln -s ../../target target) is the working approach
for enabling single-command cargo stylus check in workspace environments.

Co-Authored-By: ayush.suresh@dourolabs.xyz <byteSlayer31037@gmail.com>

target_chains/stylus/contracts/wormhole/.cargo/config.toml

@@ -1,18 +0,0 @@
-[target.wasm32-unknown-unknown]
-rustflags = [
-  "-C", "link-arg=-zstack-size=32768",
-  "-C", "target-feature=-reference-types",
-  "-C", "target-feature=+bulk-memory",
-]
-
-[target.aarch64-apple-darwin]
-rustflags = [
-"-C", "link-arg=-undefined",
-"-C", "link-arg=dynamic_lookup",
-]
-
-[target.x86_64-apple-darwin]
-rustflags = [
-"-C", "link-arg=-undefined",
-"-C", "link-arg=dynamic_lookup",
-]