* fix: do not build electron_plugin_info_host_impl.cc when plugins are disabled

it fails to build from source with this error:

../../content/public/browser/plugin_service.h:17:2: error: "Plugins should be enabled"
   17 | #error "Plugins should be enabled"

* fix: FTBFS in printing_utils.cc when ENABLE_PDF is false

* fixup! fix: do not build electron_plugin_info_host_impl.cc when plugins are disabled

fix BUILD.gn linting