Fix Bazel build

Include link-data.json as core-macros build time, so that later at
run-time the extracted sources don't have to be around anymore.

internal/core-macros/slint_doc.rs

@@ -24,10 +24,11 @@ impl syn::visit_mut::VisitMut for Visitor {
 
 impl Visitor {
     pub fn new() -> Self {
-        let link_path = concat!(env!("CARGO_MANIFEST_DIR"), "/link-data.json");
-        let link_data = std::fs::read_to_string(link_path).expect("Failed to read {link_path}");
-        let link_data: serde_json::Value =
-            serde_json::from_str(&link_data).expect("Failed to parse link-data.json");
+        let link_data: serde_json::Value = serde_json::from_str(include_str!(concat!(
+            env!("CARGO_MANIFEST_DIR"),
+            "/link-data.json"
+        )))
+        .expect("Failed to parse link-data.json");
         Self(link_data, false)
     }