convert-to-dabs calls tgz artifact, drop aicode mutator entirely

acceptance/experimental/air/convert-to-dabs/output.txt

@@ -19,13 +19,21 @@ persistent job that is not garbage-collected. When you are done, remove the
 job and its uploaded files with:
   [CLI] bundle destroy
 
-=== emitted databricks.yml (code_source_path points at ./src; no code is copied)
+=== emitted databricks.yml (code_source packaged as a tgz artifact; no code is copied)
 >>> cat databricks.yml
 bundle:
   name: torchrun-a10-smoke-test
 sync:
   paths:
     - generated_artifacts
+artifacts:
+  code_source:
+    type: tgz
+    path: .
+    include:
+      - src
+    files:
+      - source: ./dist/code_source.tgz
 targets:
   dev:
     mode: development
@@ -45,7 +53,7 @@ resources:
                 compute:
                   accelerator_type: GPU_1xA10
                   accelerator_count: 1
-            code_source_path: ./src
+            code_source_path: ./dist/code_source.tgz
       environments:
         - environment_key: default
           spec:

acceptance/experimental/air/convert-to-dabs/script

@@ -1,7 +1,7 @@
 title "convert an AIR run YAML into a DABs bundle (in place, next to the source)"
 trace $CLI experimental air convert-to-dabs train.yaml
 
-title "emitted databricks.yml (code_source_path points at ./src; no code is copied)"
+title "emitted databricks.yml (code_source packaged as a tgz artifact; no code is copied)"
 trace cat databricks.yml
 
 title "the generated command.sh carries the run command"