Add env section to bundle scripts for DABs interpolation

[shreyas-goenka]

Summary

Fixes #4179.

scripts.<name> now accepts an env: map whose values may reference ${bundle.*}, ${workspace.*}, and ${var.*}. Script content is still passed to the shell as-is (no DABs interpolation), removing the ambiguity between bundle variables and shell variables that previously forced all ${...} usage to be rejected.

scripts:
  create_lakebase_schemas:
    env:
      LAKEBASE_INSTANCE: \${var.lakebase_instance}
      LAKEBASE_DATABASE: \${var.lakebase_database}
    content: databricks psql \$LAKEBASE_INSTANCE -- -d \$LAKEBASE_DATABASE -c 'CREATE SCHEMA my_schema;'

• If an env value references a prefix that isn't resolved before scripts run (e.g. \${resources.*}), validation reports a clear error pointing at the offending env entry.
• The content-side rejection message now suggests using env: instead of just stating \${...} is unsupported.

The allowed prefixes (bundle, workspace, var/variables) match defaultPrefixes used by `ResolveVariableReferencesWithoutResources`, so values are already resolved by the time `bundle run` invokes the script.

Test plan

• `go test ./bundle/...`
• `go test ./acceptance -run 'TestAccept/bundle/run/scripts'` — happy path (`env-section`), invalid prefix (`env-bad-prefix`), updated rejection message (`no-interpolation`)
• `./task lint-q`

This pull request was AI-assisted by Isaac.