Ignore cache exporting errors in the image building workflows

[Doris-xm]

What this PR does / why we need it:
We need to manually rerun CI jobs due to cache exporting errors:

#33 exporting to GitHub Actions Cache
#33 preparing build cache for export
#33 writing layer sha256:043014c17c0e213c5220cb1c47f39ba308ecad3e3d912504a1f69cc0689bdcdd
#33 preparing build cache for export 865.0s done
#33 writing layer sha256:043014c17c0e213c5220cb1c47f39ba308ecad3e3d912504a1f69cc0689bdcdd 600.1s done
#33 ERROR: error writing layer blob: maximum timeout reached

We can ignore this with ignore-error=true, following this guide. Same work is done in kubeflow/trainer#2336

Which issue(s) this PR fixes :
Fixes #

Checklist:

• Docs included if any changes are user facing

[tenzen-y]

/rerun-all

[tenzen-y]

Thanks
/lgtm
/approve

[google-oss-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: tenzen-y

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [tenzen-y]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment