chore(block): enable `strict-boolean-expressions` rule for `eslint`

[faustbrian]

Part of https://github.com/ethereumjs/ethereumjs-monorepo/issues/2137

[codecov[bot]]

Codecov Report

Merging #2143 (e754d05) into master (b9ecb20) will increase coverage by 0.03%. The diff coverage is 92.92%.

Flag	Coverage Δ
block	92.89% <100.00%> (ø)
blockchain	88.47% <ø> (ø)
client	86.94% <ø> (ø)
common	98.09% <ø> (ø)
devp2p	92.40% <ø> (+0.02%)	:arrow_up:
ethash	∅ <ø> (∅)
evm	79.25% <ø> (ø)
rlp	∅ <ø> (∅)
statemanager	88.47% <ø> (ø)
trie	90.02% <92.52%> (+0.46%)	:arrow_up:
tx	97.98% <ø> (ø)
util	92.32% <ø> (ø)
vm	85.31% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

[faustbrian]

Will leave this marked as draft since it falls in the same category as the Uint8Array stuff at the most basic level.

[faustbrian]

Closing this since it falls in the same category as Uint8Array in terms of breaking changes/impact.