Update Golang version to fix RIE debugging

[joe4dev]

@drauedo discovered a RIE debugging issue and fixed it by upgrading the Golang version 🙇‍♂️ 👏

[drauedo]

This lgmt 🚀

Some context of what happened:
Basically the make build command was failing with the following error:

cd .. && GC_FLAGS="all=-N -l" make ARCH=x86_64 compile-lambda-linux
make[1]: Entering directory '/home/eduardo/lambda-runtime-init'
CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -buildvcs=false -ldflags "" -gcflags="all=-N -l" -o bin/aws-lambda-rie-x86_64 ./cmd/localstack
make[1]: Leaving directory '/home/eduardo/lambda-runtime-init'
docker run --rm -v $(pwd)/build-delve/:/app/ golang:1.20-bullseye \
        bash -c "cd /app && export GOARCH=amd64 && ./build.sh"
Cloning into 'delve'...
pkg/logflags/logflags.go:10:2: package log/slog is not in GOROOT (/usr/local/go/src/log/slog)
note: imported by a module that requires go 1.24
make: *** [Makefile:10: build] Error 1
mv: cannot stat 'dlv': No such file or directory
make: *** [Makefile:32: build-delve/dlv] Error 1

I believe this was failing because I'm using go 1.25. Updating the image fixed the issue. However, I'm not sure if this is something we want to do.

[gregfurman]

Neat!