refactor(core): unify removeEffectFromSubscribers() and removeStaleSubscribers()

[nerdalytics]

DUP-007

removeEffectFromSubscribers() (lines 822–828) is removeStaleSubscribers() (lines 883–888) with the filter predicate always-true:

// removeStaleSubscribers
for (const dep of prevDeps) {
    if (!newDeps.has(dep)) {
        findSubscribers(dep)?.delete(eff)
    }
}

// removeEffectFromSubscribers
for (const dep of deps) {
    findSubscribers(dep)?.delete(eff)
}

The iteration body is identical. removeStaleSubscribers could accept an optional exclude set, and removeEffectFromSubscribers becomes a call with no exclusion. Alternatively, removeEffectFromSubscribers could call removeStaleSubscribers with an empty set.