fix(parser): S3Model support empty keys (#375)

* chore: upgrade pydantic

* fix: allow empty s3 objects

Author: heitorlessa

Diff for: aws_lambda_powertools/utilities/parser/models/s3.py

@@ -4,7 +4,7 @@
 from pydantic import BaseModel
 from pydantic.fields import Field
 from pydantic.networks import IPvAnyNetwork
-from pydantic.types import PositiveInt
+from pydantic.types import NonNegativeFloat
 
 from ..types import Literal
 
@@ -43,7 +43,7 @@ class S3Bucket(BaseModel):
 
 class S3Object(BaseModel):
     key: str
-    size: PositiveInt
+    size: NonNegativeFloat
     eTag: str
     sequencer: str
     versionId: Optional[str]