Updating stemcell version in test fixtures

[wayneadams]

In our CI, we're getting test failures in the build job that look like this:

#16 19.75 github.com/concourse/bosh-io-stemcell-resource/acceptance/in_test.go:89
#16 19.75   when a regular stemcell is requested
#16 19.75   github.com/concourse/bosh-io-stemcell-resource/acceptance/in_test.go:134
#16 19.75     when the tarball is requested
#16 19.75     github.com/concourse/bosh-io-stemcell-resource/acceptance/in_test.go:154
#16 19.75       downloads the stemcell with metadata
#16 19.75       github.com/concourse/bosh-io-stemcell-resource/acceptance/in_test.go:155
#16 19.75 ------------------------------
#16 20.96 2024/07/19 01:08:49 Head "https://d26ekeud912fhb.cloudfront.net/bosh-stemcell/aws/light-bosh-stemcell-3262.4-aws-xen-ubuntu-trusty-go_agent.tgz": dial tcp: lookup d26ekeud912fhb.cloudfront.net on 10.12.0.10:53: no such host
#16 20.96 • Failure [1.207 seconds]
#16 20.96 in
#16 20.96 github.com/concourse/bosh-io-stemcell-resource/acceptance/in_test.go:89
#16 20.96   when a stemcell is requested that supports both light and regular
#16 20.96   github.com/concourse/bosh-io-stemcell-resource/acceptance/in_test.go:174
#16 20.96     downloads the light stemcell with metadata [It]
#16 20.96     github.com/concourse/bosh-io-stemcell-resource/acceptance/in_test.go:194
#16 20.96 
#16 20.96     Expected
#16 20.96         <int>: 1
#16 20.96     to equal
#16 20.96         <int>: 0
#16 20.96 
#16 20.96     github.com/concourse/bosh-io-stemcell-resource/acceptance/in_test.go:199

The cause seems to be that the stemcell URL in the fixture is no longer available.

These changes update the url and the respective version in the fixtures.

New stemcell API response: https://bosh.io/api/v1/stemcells/bosh-aws-xen-hvm-ubuntu-trusty-go_agent?all=1. Note the url and the addition of sha256.

[yharish991]

Looks like I don't have permission to provide approval here, but this LGTM!!