x/telemetry: add a process for cleaning up obsolete data

[findleyr]

Right now, there are several opportunities for the telemetry upload/aggregation process to leave behind artifacts that will never be cleaned up:

• corrupt counter files
• upload/<date>.json.lock lock files, if the process is killed during upload
• load/<date>.json files, if the process is killed during upload
• old counter files (counters older than 4w are not considered for aggregation)

Furthermore, we never delete local reports, though they cause the local folder to grow, and are likely to become obsolete over time.

The rate of growth of these files is slow, but at some point (1.24 or 1.25), we should design a system for cleaning up automatically.

CC @golang/telemetry

[gabyhelp]

Related Issues and Documentation

• x/telemetry/upload: convert old counter files to local report files #62619 (closed)
• x/telemetry: simplify state across counters, reports, mode #63218 (closed)
• x/telemetry: add garbage collection #63884
• x/telemetry: audit upload process for 1.23 #65970 (closed)

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[findleyr]

Closing as a dupe of #63884. Thanks gaby.