meta/classes: Mark do_package_write and do_build as noexec tasks

Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

meta/classes/base.bbclass

@@ -425,6 +425,7 @@ base_do_package() {
 addtask build after do_populate_sysroot
 do_build = ""
 do_build[func] = "1"
+do_build[noexec] = "1"
 do_build () {
 	:
 }

meta/classes/package.bbclass

@@ -1101,6 +1101,7 @@ addtask do_package_setscene
 do_package_write () {
 	:
 }
+do_package_write[noexec] = "1"
 do_build[recrdeptask] += "do_package_write"
 addtask package_write before do_build after do_package