Added otel SDk composer dependency

Author: HeenaBansal20

src/Exporter/Instana/composer.json

@@ -11,6 +11,7 @@
     "require": {
         "php": "^8.1",
         "open-telemetry/api": "^1.1",
+        "open-telemetry/sdk": "^1.1",
         "guzzlehttp/guzzle": "^7.4.5"
     },
     "autoload": {