crdx: Improve performance of calculateConcurrency

[leblowl]

For a simple graph with about 1000 links, the current version takes about 6 seconds on my machine and the version in this PR takes about 100ms. getSuccessors also appears to be unused now, so I removed that.

[HerbCaudill]

Hey, Lucas - I haven't been able to reproduce the poor performance of the original code. Using this benchmark, I get pretty similar performance whether I'm using the existing code or your optimized version.

auth/packages/crdx/src/graph/test/getConcurrentLinks.benchmark.ts

Lines 1 to 13 in 65c20eb

	import { getConcurrentLinks } from 'graph/index.js'
	import { buildRandomGraph } from 'util/testing/graph.js'
	import { bench, describe, expect } from 'vitest'
	describe('graphs', () => {
	const graph = buildRandomGraph(1000)
	bench('getConcurrentLinks', () => {
	for (const link of Object.values(graph.links)) {
	const concurrent = getConcurrentLinks(graph, link)
	expect(concurrent).toBeDefined()
	}
	})
	})

Would you be able to capture the experiments you've done in a benchmark?

[leblowl]

@HerbCaudill Hey, sorry I've been traveling and otherwise pretty busy lately. I will take a look and see.

[leblowl]

@HerbCaudill Just an update, I don't know when/if I will get back around to working on this, so I'm going to close this PR. If I do get to it, I'd need to open a new PR on a new branch from a personal repo anyway.