Increase stack size to 3MB (#2508)

This PR increases the stack size from the 1MB default to 3MB as per
recommendation [here](https://dfinity.slack.com/archives/CH4CADCJX/p1717748706241909?thread_ts=1716464873.584739&cid=CH4CADCJX).

I did some tests with very small stack sizes to see when
we hit errors to get a feeling for the current stack usage of II.
The tests indicate that we currently use more than 48KB but fewer than
200KB of stack.

Since we are also very lean on heap usage (~6.5 MB currently) we can
afford to increase the stack size to have more leeway with regards to
the stack.

scripts/build

@@ -120,7 +120,7 @@ function build_canister() {
     TARGET="wasm32-unknown-unknown"
     # standardize source references
     CARGO_HOME="${CARGO_HOME:-"$HOME/.cargo"}"
-    RUSTFLAGS="--remap-path-prefix $CARGO_HOME=/cargo"
+    RUSTFLAGS="--remap-path-prefix $CARGO_HOME=/cargo -C link-args=-zstack-size=3000000"
 
     cargo_build_args=(
         --manifest-path "$SRC_DIR/Cargo.toml"