fix: check active hardforks using head block for validator

[mattsse]

this should fix the Test: ForkchoiceUpdatedV2 then ForkchoiceUpdatedV3 Valid Payload Building Requests (Cancun) hive test

previously we did not enable cancun by default, only on_new_head event.

this adds a new config function with_head_timestamp that enables cancun/shanghai support based on the head block's timestamp

[Rjected]

nice, LGTM

[codecov]

Codecov Report

Merging #4882 (28aa7b9) into main (f59db31) will increase coverage by 0.01%.
The diff coverage is 100.00%.

Files	Coverage Δ
bin/reth/src/node/mod.rs	30.42% <100.00%> (+2.88%)	⬆️
crates/transaction-pool/src/validate/eth.rs	8.21% <100.00%> (+1.27%)	⬆️

... and 10 files with indirect coverage changes

Flag	Coverage Δ
integration-tests	15.50% <0.00%> (-0.01%)	⬇️
unit-tests	62.63% <100.00%> (+0.01%)	⬆️

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

Components	Coverage Δ
reth binary	32.63% <100.00%> (+0.35%)	⬆️
blockchain tree	80.44% <ø> (ø)
pipeline	88.45% <ø> (ø)
storage (db)	73.29% <ø> (ø)
trie	94.44% <ø> (-0.08%)	⬇️
txpool	49.63% <100.00%> (+0.02%)	⬆️
networking	76.12% <ø> (-0.05%)	⬇️
rpc	57.78% <ø> (-0.01%)	⬇️
consensus	61.06% <ø> (ø)
revm	28.54% <ø> (ø)
payload builder	8.16% <ø> (ø)
primitives	85.27% <ø> (ø)