internal: fix version by using dashes instead of plusses
internal: fix version by using dashes instead of plusses

https://semver.org/

This commit will be tagged v0.37.3-alpha.

Change-Id: I5b9fe28bf7e8683c1cff5211d66669acd7941708
Reviewed-on: https://code-review.googlesource.com/c/gocloud/+/39690
Reviewed-by: Tyler Bui-Palsulich <b41e4aa57d2ad7eb1b29835a1b483e209dcc3c0e@google.com>

googleapis/google-cloud-go,googleapis/google-cloud-go,googleapis/google-cloud-go,googleapis/google-cloud-go