feat: Bump Up datastore dep to v1.17.0 and Golang version to 1.21

[Zurvarian]

What type of PR is this?

Uncomment only one /kind <> line, hit enter to put that in a new line, and remove leading whitespace from that line:

/kind fix
/kind build
/kind chore
/kind ci
/kind docs
/kind style
/kind refactor
/kind perf
/kind test

/kind feat

What this PR does / Why we need it:
It increases the version of the Datastore dependency to v1.17.0 and Golang version to 1.21
This required to have access to Datastore traces in OpenTelemetry.

Which issue(s) this PR fixes:

Closes #445

Special notes for your reviewer:
Tested locally, here is an example of the new traces being exposed.

Note that sensible details have been removed.

[vasconcelosvcd]

/gcbrun

[ghost]

@Zurvarian

From the go.mod:

go 1.21
toolchain go1.21.9

The build container is complaining about an invalid statement with toolchain:

Step #3: go build -o build/server cmd/server/main.go
Step #3: go: errors parsing go.mod:
Step #3: /workspace/go.mod:5: unknown directive: toolchain
Step #3: make: *** [Makefile:48: build/server] Error 1

I suspect that we will need to ask google to create a new build container with the 1.21 golang version and toolchain for the CI pipeline to pass.

[vasconcelosvcd]

@Zurvarian

From the go.mod:

go 1.21
toolchain go1.21.9

The build container is complaining about an invalid statement with toolchain:

Step #3: go build -o build/server cmd/server/main.go
Step #3: go: errors parsing go.mod:
Step #3: /workspace/go.mod:5: unknown directive: toolchain
Step #3: make: *** [Makefile:48: build/server] Error 1

I suspect that we will need to ask google to create a new build container with the 1.21 golang version and toolchain for the CI pipeline to pass.

@loranger2k @Zurvarian I think it's a matter of upgrading the cloudrun job file here

https://github.com/googleforgames/open-saves/blob/cec978851b6b6d0fe5479271d9c6a48f5448fd80/cloudbuild.yaml#L49C17-L49C23

[Zurvarian]

Thanks for the updates, I missed the builder part.

Indeed the toolchain is a new feature from Golang 1.21 on-wards, meant to fix the exact version the code must be compiled with.
I did fix this in the Docker image, but wasn't aware of the builder.

Once we have a compatible builder I'll update the file mentioned by @vasconcelosvcd

[mbychkowski]

@Zurvarian just updated the golang builder to 1.21.

I think you will also need to update the cloudbuild.yaml in this PR for _BUILDER variable to 1.21

Then we can retry the build

[Zurvarian]

/gcbrun

[vasconcelosvcd]

/gcbrun

[vasconcelosvcd]

LGTM

[vasconcelosvcd]

/gcbrun