fix: avoid crash in symlink_package rule

When a target does not have any  in the  provider, the  rule would crash with an index out of range error.

This change adds a check to ensure the list is not empty before trying to access its elements, preventing the crash.

```
ERROR: ../2fa837e4c5ce941f68b762e5f8e7dc4d/external/rules_angular~/BUILD.bazel:8:16: in symlink_package rule @@rules_angular~//:node_modules/typescript:
Traceback (most recent call last):
        File "../2fa837e4c5ce941f68b762e5f8e7dc4d/external/rules_angular~/src/private/symlink_package.bzl", line 22, column 63, in _symlink_impl
                store_info = src[JsInfo].npm_package_store_infos.to_list()[0]
Error: index out of range (index is 0, but sequence has 0 elements)
ERROR: ../2fa837e4c5ce941f68b762e5f8e7dc4d/external/rules_angular~/BUILD.bazel:8:16: Analysis of target '@@rules_angular~//:node_modules/typescript' failed
ERROR: Analysis of target '//packages/angular/ssr/schematics:ssr_schematics_test_lib_strict_deps_test' failed; build aborted: Analysis failed
INFO: Elapsed time: 10.270s, Critical Path: 0.02s
INFO: 1 process: 1 internal.
ERROR: Build did NOT complete successfully
```

Author: alan-agius4

src/private/symlink_package.bzl

@@ -18,10 +18,11 @@ def manifest_path(ctx, file):
 
 def _symlink_impl(ctx):
     src = ctx.attr.src
-
-    store_info = src[JsInfo].npm_package_store_infos.to_list()[0]
-    src_dir = store_info.package_store_directory
-    src_workspace = src.label.workspace_name if src.label.workspace_name != "" else ctx.workspace_name
+    infos = src[JsInfo].npm_package_store_infos.to_list()
+    if len(infos) == 0:
+      src_dir = src[JsInfo].npm_sources.to_list()[0]
+    else:
+      src_dir = infos[0].package_store_directory
 
     destination = ctx.actions.declare_symlink(ctx.attr.name)
     destination_build = ctx.actions.declare_symlink(