docs: modify the project ID pattern in comment for VmImage (#162)

* docs: modifies the project ID pattern in comment for Workbench environment

PiperOrigin-RevId: 446581791

Source-Link: googleapis/googleapis@2402963

Source-Link: https://github.com/googleapis/googleapis-gen/commit/df2549f62967d22ebc803fe60cd5069dcefb9240
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google/cloud/notebooks_v1/types/environment.py

@@ -115,7 +115,7 @@ class VmImage(proto.Message):
     Attributes:
         project (str):
             Required. The name of the Google Cloud project that this VM
-            image belongs to. Format: ``projects/{project_id}``
+            image belongs to. Format: ``{project_id}``
         image_name (str):
             Use VM image name to find the image.