fix: add null checks for dbt node execution and compilation (#1695)

Co-authored-by: anandgupta42 <[email protected]>

Author: mdesmet

dbt_core_integration.py

@@ -693,6 +693,8 @@ def execute_sql(self, raw_sql: str, original_node: Optional[Union["ManifestNode"
     def execute_node(self, node: "ManifestNode") -> DbtAdapterExecutionResult:
         """Execute dbt SQL statement against database from a"ManifestNode"""
         try:
+            if node is None:
+                raise ValueError("This model doesn't exist within this dbt project")
             raw_sql: str = getattr(node, RAW_CODE)
             compiled_sql: Optional[str] = getattr(node, COMPILED_CODE, None)
             if compiled_sql:
@@ -718,6 +720,8 @@ def compile_node(
         self, node: "ManifestNode"
     ) -> Optional[DbtAdapterCompilationResult]:
         try:
+            if node is None:
+                raise ValueError("This model doesn't exist within this dbt project")
             with self.adapter.connection_named("master"):
                 return self._compile_node(node)
         except Exception as e: