apollo_deployments: retire dead preset/replacer generation machinery

Runtime (Phase 1) and the cdk8s deploy (Phase 2) now load only native config, so
the preset-replacer GENERATION machinery is dead. Remove it:
- Delete resources/app_configs/replacer_*.json (19 files), src/replacers.rs, and the
  deployment_generator bin (+ its [[bin]] entry and the tempfile dev-dep).
- service.rs: drop the replacer-annotation plumbing, the deploy-path config_to_preset/
  prune_by_is_none calls, and the orphaned ComponentConfigsSerializationWrapper. Keep
  KEYS_TO_BE_REPLACED (still feeds the retained applicative_matches_app_configs guard's
  exclusion set).
- Delete the 3 migration guard tests (deployment_files_are_up_to_date,
  replacer_config_entries_are_in_config, duplicate_config_entries). Keep the
  build_*_deserializes, applicative_matches_app_configs, and *_infra_matches_rust guards,
  and get_component_configs.

The cdk8s configList field is presence-checked only (its targets live in a different
directory and are not read under native), so deleting the base replacer JSONs leaves
synth green. apollo_deployments: 9 tests pass; cdk8s synth green for all overlays.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: nimrod-starkware

Cargo.lock

@@ -26,9 +26,4 @@ apollo_infra_utils = { workspace = true, features = ["testing"] }
 apollo_node_config = { workspace = true, features = ["testing"] }
 jrsonnet-evaluator = { workspace = true }
 jrsonnet-stdlib = { workspace = true }
-tempfile.workspace = true
 url = { workspace = true, features = ["serde"] }
-
-[[bin]]
-name = "deployment_generator"
-path = "src/bin/deployment_generator.rs"