fix chronik bridgeprimitives_tests

Summary:
D14312 broke this test

The coinbase transaction size went down from 108 bytes to 106 bytes for 200 blocks.

Test Plan:

cmake .. -GNinja -DBUILD_BITCOIN_CHRONIK=ON
ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D14313