debug ci, remove ignore-optional flag

[alik-agaev]

Description and Related Issue(s)

This should fix random build errors like theese:

• https://github.com/blockscout/frontend/actions/runs/7611992441/job/20728605248#step:8:508
• https://github.com/blockscout/frontend/actions/runs/7582933840/job/20654796170#step:8:666

There are no effects on build time or artifact size.

Checklist for PR author

• I have tested these changes locally.
• I added tests to cover any new functionality, following this guide
• Whenever I fix a bug, I include a regression test to ensure that the bug does not reappear silently.
• If I have added, changed, renamed, or removed an environment variable, I have updated the list of environment variables in the documentation and made the necessary changes to the validator script according to the guide