[CI] chore: remove QNN and python DML from release meta-pipeline (#28077)

### Description

Remove QNN EP and python DML pipelines from release packaging pipeline
requirements.

### Motivation and Context

Both are deprecated.

Author: sanaa-hamel-microsoft

tools/ci_build/github/azure-pipelines/main-release-pipeline.yml

@@ -43,16 +43,6 @@ parameters:
   type: boolean
   default: true
 
-- name: python_dml_packaging
-  displayName: 'Run Python DML Packaging Pipeline (1625)'
-  type: boolean
-  default: true
-
-- name: qnn_nuget_packaging
-  displayName: 'Run QNN_Nuget_Windows (1234)'
-  type: boolean
-  default: true
-
 - name: dml_nuget_packaging
   displayName: 'Run DML Nuget Pipeline (1994)'
   type: boolean

tools/python/trigger_and_wait_pipelines.py

@@ -160,8 +160,10 @@ class PipelineStatusRecord:
         key="webgpu_python_packaging",
     ),
 ]
+assert len({cfg.id for cfg in PIPELINE_REGISTRY}) == len(PIPELINE_REGISTRY), "Pipeline IDs must be unique"
 
 _PIPELINE_KEY_TO_ID: dict[str, int] = {cfg.key: cfg.id for cfg in PIPELINE_REGISTRY}
+assert len(_PIPELINE_KEY_TO_ID) == len(PIPELINE_REGISTRY), "Pipeline keys must be unique"
 
 
 def get_token() -> str:
@@ -372,6 +374,8 @@ def _parse_enable_flags(raw: list[str]) -> dict[int, bool]:
         key = key.strip()
         if key not in _PIPELINE_KEY_TO_ID:
             logger.warning("##[warning]Unknown pipeline key: %s", key)
+            # invalid key -> non-empty set -> ensures that we don't enable all pipelines if we don't recognise one.
+            result[-1] = False
             continue
         result[_PIPELINE_KEY_TO_ID[key]] = val.strip().lower() == "true"
     return result
@@ -385,6 +389,10 @@ def _read_enable_flags_from_env() -> dict[int, bool]:
             continue
         pipeline_key = key[len(prefix) :].lower()
         if pipeline_key not in _PIPELINE_KEY_TO_ID:
+            # Given that env vars are a swamp for config, just assume it wasn't meant for us.
+            # Still warn about it, however.
+            # n.b. this differs in behaviour from cmd-ln parsing, where we mark unrecognised keys.
+            logger.warning("##[warning]Unknown pipeline key in env-vars, ignoring: %s", key)
             continue
         result[_PIPELINE_KEY_TO_ID[pipeline_key]] = value.strip().lower() == "true"
     return result
@@ -403,12 +411,15 @@ def main() -> int:
 
     configs = list(PIPELINE_REGISTRY)
 
-    # fetch the pipeline enable/disable flags
+    # No explicit pipeline enable/disable -> use everything.
+    # Specify any pipeline -> opt-in only.
+    # We can add partial opt-out in the future if we need it.
+    # Consequence `argv=['--enable-pipeline', 'A=false']` => nothing enabled.
     enable_flags = _parse_enable_flags(args.enable_pipeline)
     if not enable_flags:
         enable_flags = _read_enable_flags_from_env()
     if enable_flags:
-        configs = [cfg for cfg in configs if enable_flags.get(cfg.id, True)]
+        configs = [cfg for cfg in configs if enable_flags.get(cfg.id, False)]
 
     if args.pre_release_suffix_string:
         for cfg in configs:
@@ -445,12 +456,14 @@ def main() -> int:
     kusto_client = _create_kusto_client()
 
     triggered: list[TriggeredRun] = []
+    trigger_failed: list[PipelineConfig] = []
     for cfg in configs:
         run = trigger_pipeline(cfg, branch, token)
         if run:
             triggered.append(run)
             publish_run_status(run, branch, kusto_client)
         else:
+            trigger_failed.append(cfg)
             logger.error("##[error]Failed to trigger '%s'", cfg.name)
 
     if not triggered:
@@ -474,6 +487,12 @@ def main() -> int:
     any_failed = any(run.result != BuildResult.SUCCEEDED for run in triggered)
 
     logger.info("=" * 60)
+    # re-iterate pipelines that failed to trigger so they're not lost at the top of the log
+    for cfg in trigger_failed:
+        logger.error("  [%d] %s (project: %s) - FAILED TO TRIGGER", cfg.id, cfg.name, cfg.project)
+        if cfg.template_parameters:
+            logger.error("       Template params: %s", cfg.template_parameters)
+
     for run in triggered:
         status = "PASS" if run.result == BuildResult.SUCCEEDED else "FAIL"
         if run.result == BuildResult.SUCCEEDED: