network-manager-applet: Package gir-1.0 files into devel package

Fixes QA errors e.g.

ERROR: network-manager-applet-1.8.10-r0 do_package: QA Issue: network-manager-applet: Files/directories were installed but not shipped in any package:
/usr/share/gir-1.0

---
V2:
- Add a comment explaining reason for packaging gir files

 .../network-manager-applet/network-manager-applet_1.8.10.bb  | 5 +++++
 1 file changed, 5 insertions(+)

index dc2b964be5..91ae8b740b 100644
@@ -43,3 +43,8 @@ FILES_${PN} += " \
     ${datadir}/libnm-gtk/wifi.ui \
     ${datadir}/libnma/wifi.ui \
 "
+
+# musl builds generate gir files which otherwise go un-packaged
+FILES_${PN}-dev += " \
+    ${datadir}/gir-1.0 \
+"

2.17.0