[configure] post-release bump to 2.29.4
[configure] post-release bump to 2.29.4

fanc999/libsoup,ahmedammar/platform_external_gst_libsoup,ahmedammar/platform_external_gst_libsoup,Distrotech/libsoup,jwendell/libsoup,Distrotech/libsoup,jwendell/libsoup,jwendell/libsoup,fanc999/libsoup,jwendell/libsoup,Distrotech/libsoup,Distrotech/libsoup,fanc999/libsoup,fanc999/libsoup,ahmedammar/platform_external_gst_libsoup,Distrotech/libsoup,jwendell/libsoup,fanc999/libsoup