Update Dask-on-Ray version

[ci] Pin prometheus_client to fix current test outages (ray-project#2…

…3749)

What: Pins prometheus_client to < 0.14.0, hopefully fixing today's CI outages
Why: New version of the python client (https://github.com/prometheus/client_python/releases) breaks our CI

Update ray version from 1.12.0rc1 to 1.12.0 (ray-project#23806)

Update ray version from 1.12.0rc1 to 1.12.0 (ray-project#23806)

Operator does not retry monitor on failure. (ray-project#22792) (ray-…

…project#22804)

Co-authored-by: Dmitri Gekhtman <[email protected]>

Use latest cmake for pipelined_ingestion and pipelined_training tests (…

…ray-project#21674)

[Java] Bump log4j 2.16.0 -> 2.17.0 (ray-project#21176)

Resolves [CVE-2021-45105](GHSA-p6xc-xr62-6r2g).

[Java] Bump Log4j2 to completely remove lookups (ray-project#21081)

As per the 2.16.0 release of Lo4j2, Lookup support is removed 🎉 
https://logging.apache.org/log4j/2.x/changes-report.html#a2.16.0

[Datasets] Last-mile preprocessing docs. (ray-project#20712)

Datasets docs for last-mile preprocessing, particularly geared towards ML ingest. This gives groupby, aggregations, and random shuffling examples in the overview page (not present previously), adds some concreteness to our last-mile preprocessing positioning, and provides some preprocessing recipes for a few common transformations.

Revert change to set debug info to -g1 (ray-project#19900)