[release/9.0] Use correct name for AZL3 build image

[akoeplinger]

Backport of #16510

To double check:

• The right tests are in and the right validation has happened. Guidance: https://github.com/dotnet/arcade/blob/main/Documentation/Validation.md

[akoeplinger]

/backport to release/8.0

[github-actions]

Started backporting to release/8.0 (link to workflow run)

[github-actions]

@akoeplinger backporting to release/8.0 failed, the patch most likely resulted in conflicts. Please backport manually!

git am output

$ git am --3way --empty=keep --ignore-whitespace --keep-non-patch changes.patch

Applying: [release/9.0] Use correct name for AZL3 build image
Using index info to reconstruct a base tree...
A	eng/common/core-templates/job/source-build.yml
Falling back to patching base and 3-way merge...
Auto-merging eng/common/templates-official/job/source-build.yml
CONFLICT (content): Merge conflict in eng/common/templates-official/job/source-build.yml
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
hint: When you have resolved this problem, run "git am --continue".
hint: If you prefer to skip this patch, run "git am --skip" instead.
hint: To restore the original branch and stop patching, run "git am --abort".
hint: Disable this message with "git config set advice.mergeConflict false"
Patch failed at 0001 [release/9.0] Use correct name for AZL3 build image
Error: The process '/usr/bin/git' failed with exit code 128

Link to workflow output