try capability rename

Author: pabloem

x-pack/plugin/esql/qa/testFixtures/src/main/resources/k8s-timeseries.csv-spec

@@ -723,7 +723,7 @@ mx:integer | tbucket:datetime
 
 derivative_of_gauge_metric
 required_capability: ts_command_v0
-required_capability: ts_linreg
+required_capability: TS_LINREG_DERIVATIVE
 
 TS k8s
 | WHERE pod == "three"
@@ -745,7 +745,7 @@ max_deriv:double | time_bucket:datetime     | pod:keyword
 
 derivative_compared_to_rate
 required_capability: ts_command_v0
-required_capability: ts_linreg
+required_capability: TS_LINREG_DERIVATIVE
 
 TS k8s
 | STATS max_deriv = max(deriv(to_long(network.total_bytes_in))), max_rate = max(rate(network.total_bytes_in)) BY time_bucket = bucket(@timestamp,5minute), cluster

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/action/EsqlCapabilities.java

@@ -1477,7 +1477,7 @@ public enum Cap {
          */
         PERCENTILE_OVER_TIME,
         VARIANCE_STDDEV_OVER_TIME,
-        TS_LINREG,
+        TS_LINREG_DERIVATIVE,
         /**
          * INLINE STATS fix incorrect prunning of null filtering
          * https://github.com/elastic/elasticsearch/pull/135011