chore: use pmtree instead of vacp2p_pmtree

[rymnc]

Now that the changes we require are upstream, using pmtree's crate

[github-actions]

Benchmark for 0941720

Click to view benchmark

Test	Base	PR	%
FullMerkleTree::delete	1217.9±2.30ns	1217.0±2.26ns	-0.07%
FullMerkleTree::get	0.1±0.00ns	0.1±0.00ns	0.00%
FullMerkleTree::override_range	3.0±0.00µs	3.0±0.00µs	0.00%
FullMerkleTree::set	1219.5±1.64ns	1218.5±1.78ns	-0.08%
OptimalMerkleTree::compute_root	1431.5±62.76ns	1410.7±2.51ns	-1.45%
OptimalMerkleTree::delete	1418.2±1.88ns	1396.3±1.51ns	-1.54%
OptimalMerkleTree::get	30.4±0.06ns	30.6±0.05ns	+0.66%
OptimalMerkleTree::override_range	7.0±0.00µs	7.1±0.01µs	+1.43%
OptimalMerkleTree::set	1379.3±2.13ns	1373.8±3.39ns	-0.40%

[github-actions]

Benchmark for 0941720

Click to view benchmark

Test	Base	PR	%
Pmtree::compute_root	2.5±0.06ns	2.0±0.01ns	-20.00%
Pmtree::get	565.5±0.77ns	571.0±20.21ns	+0.97%
Pmtree::override_range	216.8±24.73µs	223.4±27.46µs	+3.04%
Pmtree::set	78.7±0.55µs	79.5±0.61µs	+1.02%
Pmtree:delete	80.1±2.34µs	79.6±0.15µs	-0.62%