bug(Osaka): `TARGET_BLOB_GAS_PER_BLOCK` should not be an independent constant

[gurukamath]

TARGET_BLOB_GAS_PER_BLOCK should be GAS_PER_BLOB * BLOB_SCHEDULE_TARGET. Having GAS_PER_BLOB and BLOB_SCHEDULE_TARGET as well as TARGET_BLOB_GAS_PER_BLOCK as independently defined constants creates 2 sources of truth and room for potential bugs

Please refer to this PR for more context on this