bundle.bbclass: do not generate SSTATE artifacts

The artifacts created are quite large and keeping multiple of them
will consume a notable amount of disk space while the expected speed-up
is minimal.
(For the same reasons, the image class does not generate SSTATE
artifacts).

Having SSTATE artifacts for bundles enabled can also lead to
unexpected/unwanted behavior if a rootfs image recipe was rebuild
and the binary output (file system image) changed but did not make it
into the final bundle.
This becomes a major problem, e.g. in the context of verified boot.

Signed-off-by: Enrico Jörns <[email protected]>
(cherry picked from commit b5be595)
Signed-off-by: Enrico Jörns <[email protected]>

classes/bundle.bbclass

@@ -453,6 +453,8 @@ addtask bundle after do_configure
 
 inherit deploy
 
+SSTATE_SKIP_CREATION:task-deploy = '1'
+
 do_deploy() {
 	install -d ${DEPLOYDIR}
 	install -m 0644 ${B}/bundle.raucb ${DEPLOYDIR}/${BUNDLE_NAME}${BUNDLE_EXTENSION}