Rust: set ignore on code example in comment

I found that `cargo test` fails without this, because even with `no_run`, Cargo
will still try to compile the code. It would be nice to have a working example
here, but unfortunately it's non-trivial to set that up since we would need a
real generated proto.

I also tweaked cargo_test.sh to run the doc tests so that we have CI coverage
for those.

PiperOrigin-RevId: 703611549

rust/proto_macro.rs

@@ -13,7 +13,7 @@
 /// require another call to this macro in order to return a submessage
 /// literal.
 ///
-/// ```rust,no_run
+/// ```rust,ignore
 /// /*
 /// Given the following proto definition:
 /// message Data {

rust/release_crates/cargo_test.sh

@@ -59,12 +59,11 @@ echo "Expanding protobuf_example crate tar"
 tar -xvf $EXAMPLE_TAR -C $EXAMPLE_ROOT 
 
 cd $CRATE_ROOT
-# Run all tests except doctests
-CARGO_HOME=$CARGO_HOME cargo test --lib --bins --tests
+CARGO_HOME=$CARGO_HOME cargo test
 CARGO_HOME=$CARGO_HOME cargo publish --dry-run
 
 cd $CODEGEN_ROOT
-CARGO_HOME=$CARGO_HOME cargo test --lib --bins --tests
+CARGO_HOME=$CARGO_HOME cargo test
 CARGO_HOME=$CARGO_HOME cargo publish --dry-run
 
 cd $EXAMPLE_ROOT