TSDB: fix time series field caps bwc yaml test (#89236)

Stops the repeated test failures due to #89171

rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/field_caps/40_time_series.yml

@@ -1,8 +1,8 @@
 ---
 setup:
   - skip:
-      version: " - 7.99.99"
-      reason: introduced in 8.0.0
+      version: " - 8.0.99"
+      reason: introduced in 8.1.0
 
   - do:
       indices.create:
@@ -110,8 +110,8 @@ setup:
 "Get simple time series field caps":
 
   - skip:
-      version: " - 7.99.99"
-      reason: introduced in 8.0.0
+      version: " - 8.0.99"
+      reason: introduced in 8.1.0
 
   - do:
       field_caps:
@@ -172,8 +172,8 @@ setup:
 "Get time series field caps with conflicts":
 
   - skip:
-      version: " - 7.99.99"
-      reason: introduced in 8.0.0
+      version: " - 8.0.99"
+      reason: introduced in 8.1.0
 
   - do:
       field_caps: