Do not set pinned mongodb version in tav.

Author: onurtemizkan

plugins/node/opentelemetry-instrumentation-mongodb/package.json

@@ -10,7 +10,7 @@
     "test": "npm run test-v3 && npm run test-v4 && npm run test-v5-v6 && nyc merge .nyc_output ./coverage/coverage-final.json",
     "test-v3": "tav mongodb 3.7.4 npm run test-v3-run",
     "test-v4": "tav mongodb 4.17.0 npm run test-v4-run",
-    "test-v5-v6": "tav mongodb 6.8.0 npm run test-v5-v6-run",
+    "test-v5-v6": "npm run test-v5-v6-run",
     "test-v3-run": "nyc --no-clean mocha --require '@opentelemetry/contrib-test-utils' 'test/**/mongodb-v3.test.ts'",
     "test-v4-run": "nyc --no-clean mocha --require '@opentelemetry/contrib-test-utils' 'test/mongodb-v4-v5-v6.metrics.test.ts' 'test/**/mongodb-v4.test.ts'",
     "test-v5-v6-run": "nyc --no-clean mocha --require '@opentelemetry/contrib-test-utils' 'test/mongodb-v4-v5-v6.metrics.test.ts' 'test/**/mongodb-v5-v6.test.ts'",