Improve validator key cache lock handling (#1837)
Improve validator key cache lock handling (#1837)

## Issue Addressed

NA

## Proposed Changes

Improves the deletion of the validator key cache lock file in case of program interrupts.

## Additional Info

This should reduce cases where a lock file doesn't get removed on shutdown and reduce complaints on Discord. This will be superseded by issue #1823.



sigp/lighthouse,sigp/lighthouse,sigp/lighthouse,sigp/lighthouse