test/link: don't strip producers section for wasm

When testing the Wasm linker for the producers section
we do not ever want to strip the binary as this will remove
the producers section in release-small.

This fixes the CI errors by d086b371f0

test/link/wasm/producers/build.zig

@@ -14,6 +14,7 @@ pub fn build(b: *Builder) void {
     lib.use_llvm = false;
     lib.use_stage1 = false;
     lib.use_lld = false;
+    lib.strip = false;
     lib.install();
 
     const zig_version = builtin.zig_version;