update benchmarks task on evergreen

Author: adelinowona

evergreen/evergreen.yml

@@ -1461,19 +1461,7 @@ tasks:
         - func: bootstrap-mongo-orchestration
         - func: run-smoke-tests
 
-    - name: performance-tests-net80-server-v6.0
-      commands:
-        - func: bootstrap-mongo-orchestration
-          vars:
-            VERSION: "v6.0-perf"
-            TOPOLOGY: "server"
-            SSL: "nossl"
-            AUTH: "noauth"
-            SKIP_LEGACY_SHELL: "true"
-        - func: install-dotnet
-        - func: run-performance-tests
-
-    - name: performance-tests-net80-server-v8.0
+    - name: test-csharp-spec-benchmarks
       commands:
         - func: bootstrap-mongo-orchestration
           vars:
@@ -2539,8 +2527,7 @@ buildvariants:
   run_on:
     - rhel90-dbx-perf-large
   tasks:
-    - name: performance-tests-net80-server-v6.0
-    - name: performance-tests-net80-server-v8.0
+    - name: test-csharp-spec-benchmarks
 
 # AWS Lambda tests
 - name: aws-lambda-tests