manifest: Update poky to dunfell-23.0.3
Update poky to the latest dunfell-23.0.3 tag aka Yocto Project 3.1.3.
Because the meta-openembedded layer is not fixed versioned simple take the most recent dunfell branch version.
Change-Id: I3ad651b61e96e6551daa99edd45e5b8d10570149