chore: Add index for better performance on server for datasource storage (#29676)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **Database Enhancements**
- Implemented a new compound index to improve the performance of queries
on the `DatasourceStorage` collection, specifically for `environmentId`
and `deleted` fields.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: Arpit Mohan <mohanarpit@users.noreply.github.com>

app/server/appsmith-server/src/main/java/com/appsmith/server/migrations/db/ce/Migration039AddCompoundIndexForDatasourceStorage.java

@@ -0,0 +1,53 @@
+package com.appsmith.server.migrations.db.ce;
+
+import com.appsmith.external.models.DatasourceStorage;
+import com.appsmith.server.constants.FieldName;
+import io.mongock.api.annotations.ChangeUnit;
+import io.mongock.api.annotations.Execution;
+import io.mongock.api.annotations.RollbackExecution;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.data.mongodb.UncategorizedMongoDbException;
+import org.springframework.data.mongodb.core.MongoTemplate;
+import org.springframework.data.mongodb.core.index.Index;
+
+import static com.appsmith.server.migrations.DatabaseChangelog1.dropIndexIfExists;
+import static com.appsmith.server.migrations.DatabaseChangelog1.ensureIndexes;
+import static com.appsmith.server.migrations.DatabaseChangelog1.makeIndex;
+
+@Slf4j
+@ChangeUnit(order = "039", id = "add-compound-index-datasource-storage", author = " ")
+public class Migration039AddCompoundIndexForDatasourceStorage {
+
+    private final MongoTemplate mongoTemplate;
+
+    private static final String DATASOURCE_STORAGE_COMPOUND_INDEX = "environmentId_1_deleted_1";
+
+    public Migration039AddCompoundIndexForDatasourceStorage(MongoTemplate mongoTemplate) {
+        this.mongoTemplate = mongoTemplate;
+    }
+
+    /**
+     * Not a critical migration, so we can skip the rollback.
+     */
+    @RollbackExecution
+    public void rollbackExecution() {}
+
+    @Execution
+    public void addIndexInDatasourceStorageCollection() {
+
+        Index compoundIndex =
+                makeIndex(FieldName.ENVIRONMENT_ID, FieldName.DELETED).named(DATASOURCE_STORAGE_COMPOUND_INDEX);
+
+        try {
+            dropIndexIfExists(mongoTemplate, DatasourceStorage.class, DATASOURCE_STORAGE_COMPOUND_INDEX);
+            ensureIndexes(mongoTemplate, DatasourceStorage.class, compoundIndex);
+        } catch (UncategorizedMongoDbException mongockException) {
+            log.error(
+                    "An error occurred while creating the index : {}, skipping the addition of index because of {}.",
+                    DATASOURCE_STORAGE_COMPOUND_INDEX,
+                    mongockException.getMessage());
+        } catch (Exception exception) {
+            log.error("An error occurred while creating the index : {}", DATASOURCE_STORAGE_COMPOUND_INDEX, exception);
+        }
+    }
+}