ci: fix missing getVersion in nightly Dafny CI

[alex-chew]

Fixes startup failures like https://github.com/aws/aws-cryptographic-material-providers-library/actions/runs/11389253918

The getVersion job definition is copied from

aws-cryptographic-material-providers-library/.github/workflows/daily_ci.yml

Lines 9 to 12 in 787f63a

	getVersion:
	# Don't run the cron builds on forks
	if: github.event_name != 'schedule' || github.repository_owner == 'aws'
	uses: ./.github/workflows/dafny_version.yaml

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[alex-chew]

Test run of nightly: https://github.com/aws/aws-cryptographic-material-providers-library/actions/runs/11394157649

Note that it fails as expected due to a different error related to an out-of-date Smithy dependency. The fact that the jobs run at all indicates that the PR successfully fixes the invalid workflow file.