upload error during stress testing

[migmartri]

{"level":"info","ts":1696448527.64371,"kind":"server","component":"grpc","operation":"/cas.v1.StatusService/Statusz","args":"readiness:true","code":0,"reason":"","stack":"","latency":0.00006399}
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0xa265a1]

goroutine 245650 [running]:
github.com/chainloop-dev/chainloop/app/artifact-cas/internal/service.bufferStream({0x12814f0, 0xc0004627b0}, {0x1286c38, 0xc00576c480}, 0xc005a42420, 0xc0001391a0)
        /home/runner/work/chainloop/chainloop/app/artifact-cas/internal/service/bytestream.go:196 +0x141
created by github.com/chainloop-dev/chainloop/app/artifact-cas/internal/service.(*ByteStreamService).Write in goroutine 245588
        /home/runner/work/chainloop/chainloop/app/artifact-cas/internal/service/bytestream.go:100 +0x6b8

The error happens in this line

chainloop/app/artifact-cas/internal/service/bytestream.go

Line 196 in 4b8af6e

if errors.Is(err, io.EOF) || req.GetFinishWrite() {

and it's likely to happen because the client timeouts or looses connection. Canceling the connection also causes the pod to fail