Avoid LinkingTo dependencies in package resolution

Packages listed under LinkingTo are required for building dependent
packages, but not at runtime as they are header-only or statically
linked libraries.

So, we can ignore these packages when we're looking for dependencies to
bundle for webR. In webR 0.4.1, these packages will also be ignored
when invoking `webr::install()`.

R/packages.R

@@ -6,15 +6,16 @@ sys_env_max_filesize <- function() {
   if (max_fs_env == "") NULL else max_fs_env
 }
 
-# Resolve package list hard dependencies
+# Resolve package list, dependencies listed in Depends and Imports
 resolve_dependencies <- function(pkgs, local = TRUE) {
   pkg_refs <- if (local) {
     refs <- find.package(pkgs, lib.loc = NULL, quiet = FALSE, !is_quiet())
     glue::glue("local::{refs}")
   } else {
     pkgs
   }
-  inst <- pkgdepends::new_pkg_deps(pkg_refs)
+  wasm_config <- list(dependencies = c("Depends", "Imports"))
+  inst <- pkgdepends::new_pkg_deps(pkg_refs, config = wasm_config)
   inst$resolve()
   unique(inst$get_resolution()$package)
 }