This removes auto-configuration of the snap.*.ethdisco.net DNS discovery tree.
Since measurements have shown that > 75% of nodes in all.*.ethdisco.net support
snap, we have decided to retire the dedicated index for snap and just use the eth
tree instead.

The dial iterators of eth and snap now use the same DNS tree in the default configuration,
so both iterators should use the same DNS discovery client instance. This ensures that
the record cache and rate limit are shared. Records will not be requested multiple times.

While testing the change, I noticed that duplicate DNS requests do happen even
when the client instance is shared. This is because the two iterators request the tree
root, link tree root, and first levels of the tree in lockstep. To avoid this problem, the
change also adds a singleflight.Group instance in the client. When one iterator
attempts to resolve an entry which is already being resolved, the singleflight object
waits for the existing resolve call to finish and returns the entry to both places.

eth: don't print db upgrade warning on db init

core: remove old conversion to shuffle leveldb blocks into ancients

* params: remove dependency on crypto

Package params should not depend on package crypto because building
crypto requires cgo.

Since build/ci.go needs package params to get the go-ethereum version
number, C code must be compiled in order to run the build tool, which is
annoying for certain cross-compilation setups.

* params: add SectionHead

* Fix interpreter comment

* Fix comment

Do not keep separate flag for "max code size exceeded" case, but instead
assign appropriate error for it sooner.

This PR fixes a couple of issues in the eth test suite that caused flakiness when run in the CI.

eth/protocols/snap: use storage batch, not account batch in st task

core, eth: abort snapshot generation on snap sync and resume later

eth: restore eth_hashrate API endpoint

core, eth, ethdb, trie: simplify range proofs

* trie: add benchmark for proofless range

* trie: remove unused returns + use stacktrie

eth/protocols/snap: lower the packet size to avoid overloading link

* les, tests: fix les clientpool

* tests: disable debug mode

* les: polish code

Add more cross-fuzzers to fuzz bls with gnark versus geth's own bls12-381 library

This PR makes the gas price oracle ignore transactions priced at `<=1 wei`.

p2p/tracker: only reschedule wake if previous didn't run