some github runner failers

[Paul D]

https://github.com/openwrt/packages/actions/runs/7908507874/job/21587828762?pr=23415

for various platforms

errors:


#4 [internal] load metadata for 
docker.io/openwrt/rootfs:i386_pentium-mmx-openwrt-23.05
#4 ERROR: no match for platform in manifest 
sha256:7a53f3d962d2ecbd00ee1f5b12794be788ca9312c1f2bc51d4ff36376a2b362d: 
not found
------
  > [internal] load metadata for 
docker.io/openwrt/rootfs:i386_pentium-mmx-openwrt-23.05:
------
Dockerfile:2
--------------------
    1 |     ARG ARCH=x86-64
    2 | >>> FROM openwrt/rootfs:$ARCH
    3 |
    4 |     ADD entrypoint.sh /entrypoint.sh
--------------------
ERROR: failed to solve: openwrt/rootfs:i386_pentium-mmx-openwrt-23.05: 
no match for platform in manifest 
sha256:7a53f3d962d2ecbd00ee1f5b12794be788ca9312c1f2bc51d4ff36376a2b362d: 
not found
Error: Process completed with exit code 1.