correct latest-dev-version file (#15444)

In #15299 we changed the versioning
scheme of dev releases slightly, as npm and python have slightly
different requirements. However this also means that names of CLI dev
releases changed, and thus downloads failed.

Fix that by updating the latest-dev-version file to the new versioning
scheme.

Fixes #15443

## Checklist

- [ ] I have run `make tidy` to update any new dependencies
- [ ] I have run `make lint` to verify my code passes the lint check
  - [ ] I have formatted my code using `gofumpt`

<!--- Please provide details if the checkbox below is to be left
unchecked. -->
- [ ] I have added tests that prove my fix is effective or that my
feature works
<!--- 
User-facing changes require a CHANGELOG entry.
-->
- [ ] I have run `make changelog` and committed the
`changelog/pending/<file>` documenting my change
<!--
If the change(s) in this PR is a modification of an existing call to the
Pulumi Cloud,
then the service should honor older versions of the CLI where this
change would not exist.
You must then bump the API version in
/pkg/backend/httpstate/client/api.go, as well as add
it to the service.
-->
- [ ] Yes, there are changes in this PR that warrants bumping the Pulumi
Cloud API version
<!-- @pulumi employees: If yes, you must submit corresponding changes in
the service repo. -->

.github/workflows/on-merge.yml

@@ -72,7 +72,7 @@ jobs:
 
   update-dev-version:
     name: update-dev-version
-    needs: [dev-release]
+    needs: [dev-release, info]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
@@ -93,11 +93,9 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.PULUMI_BOT_TOKEN }}
         run: |
-          version="${{ steps.ghd.outputs.describe }}"
-          # the git describe output includes a 'v' prefix, but we
-          # don't expect that in the latest-dev-version file.  Strip
-          # it here.
-          version="${version#v}"
+          short_sha="${{ steps.ghd.outputs.short-sha }}"
+          version="${{ needs.info.outputs.version }}"
+          version="${version#v}-alpha.${short_sha}"
           pulumictl dispatch -c pulumi-cli-dev-version -r pulumi/docs dev_version="$version"
 
   ci-ok: