fix(deps): update dependency grpc to v4

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
grpc	dependencies	major	^3.1.0 -> ^4.0.0

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Release Notes

grpc/grpc-dart (grpc)

v4.0.1

Compare Source

• Fix header and trailing not completing if the call is terminated. Fixes #​727

v4.0.0

Compare Source

• Set compressed flag correctly for grpc-encoding = identity. Fixes #​669 (https://github.com/grpc/grpc-dart/pull/693)
• Remove generated status codes.
• Remove dependency on package:archive.
• Move codec.dart.
• Work around hang during Flutter hot restart by adding default case handler in _GrpcWebConversionSink.add.

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