chore: Restore 0xB96b maxFillSize

[pxrl]

This relayer is performing well based on initial testing.

📥 Relayer Configuration Added

This PR adds a new configuration file inside the /configs directory for the relayer.

👤 Operator Information

You may provide the following details before submitting your PR. Alternatively, you can reach out to the Across team via private channels.

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🧪 Verification Checklist

• I have added my configuration file in the /configs directory.
• I have ensured no other files have been modified.
• I have successfully run the validation script: yarn validate-configs (Optional - this check also runs as a job in CI)