[VS Incentives]: Fallback to latest weights if fails to sync

[p0mvn]

Background

In the current design, we fail to allocate to all gauges within the group if at least one pool fails to sync volume:

osmosis/x/incentives/keeper/distribute.go

Lines 39 to 43 in 76fda98

	err := k.syncGroupWeights(ctx, group)
	if err != nil {
	ctx.Logger().Error("error syncing group gauge weights, skipping", "group gauge id", group.GroupGaugeId, "error", err.Error())
	continue
	}

In that case, incentives stay in the group gauge and get distributed as long as all pools have their volumes updated.

This is undesirable since new pools are likely to have low volume. As a result, all pools associated with such new pools might miss the incentives completely until volume ramps up for all pools.

Additionally, this might cause challenges for external projects incentivizing groups where some of the pools are low-volume

Suggested Design

We should implement the mechanism so that distribution falls back to the old weights if synching fails (as long as they exist)

Acceptance Criteria

• fallback mechanism implemented
• tests updated