ESQL: Use a 9.3-exclusive version for exp. histogram

[alex-spies]

#137432 added a minimum transport version to data types that are under construction, so that even in SNAPSHOT builds a coordinator node can decide whether other nodes or clusters are new enough to understand a data type that recently became supported in ESQL.

The EXPONENTIAL_HISTOGRAM type is one such type that is currently under construction. #137432 wrongly gave it a minimum transport version that was also backported to 9.2, even though the type is exclusive to 9.3 so far (even in SNAPSHOT builds).

To keep things consistent, use a newer minimum transport version for EXPONENTIAL_HISTOGRAM, namely the first version after it was added which was also not backported to 9.2.

(There wasn't any breakage from this because we don't have tests that do anything with EXPONENTIAL_HISTOGRAM in mixed 9.2/9.3 clusters/CCS to my knowledge.)

[elasticsearchmachine]

Pinging @elastic/es-analytical-engine (Team:Analytics)

[JonasKunz]

There wasn't any breakage from this because we don't have tests that do anything with EXPONENTIAL_HISTOGRAM in mixed 9.2/9.3 clusters/CCS to my knowledge.

Correct. exponential_histograms participate in mixed cluster tests via the CSV tests, but those are guarded by a capability which has been renamed with every change. So effectively they only run on homogenous, latest clusters.