test(sql): scope yaml profile test to demo cases

Remove sql.explain.json and trim sql.profile.yml to two demo cases:
happy path and "ignored for csv format". The csv case demonstrates the
silently-ignored behavior using the same `sql:` action, removing the
need for the sql.explain.json spec.

The remaining sql.json spec is required: every test case dispatches
through the `sql:` action.

Refs: opensearch-project#5317
Signed-off-by: Chen Dai <daichen@amazon.com>

Author: dai-chen

integ-test/src/yamlRestTest/resources/rest-api-spec/api/sql.explain.json

@@ -59,21 +59,6 @@ teardown:
   - gt: {profile.plan.time_ms: 0.0}
   - match: {profile.plan.rows: 2}
 
----
-"Profile ignored for explain api":
-  - skip:
-      features:
-        - headers
-        - allowed_warnings
-  - do:
-      headers:
-        Content-Type: 'application/json'
-      sql.explain:
-        body:
-          query: 'SELECT message FROM sql_profile'
-          profile: true
-  - match: {profile: null}
-
 ---
 "Profile ignored for csv format":
   - skip:
@@ -89,32 +74,3 @@ teardown:
           profile: true
         format: 'csv'
   - match: {profile: null}
-
----
-"Profile absent when not requested":
-  - skip:
-      features:
-        - headers
-        - allowed_warnings
-  - do:
-      headers:
-        Content-Type: 'application/json'
-      sql:
-        body:
-          query: 'SELECT message FROM sql_profile'
-  - match: {profile: null}
-
----
-"Profile ignored for explain query":
-  - skip:
-      features:
-        - headers
-        - allowed_warnings
-  - do:
-      headers:
-        Content-Type: 'application/json'
-      sql:
-        body:
-          query: 'EXPLAIN SELECT message FROM sql_profile'
-          profile: true
-  - match: {profile: null}