feat(pipelines): add executePublish parameter to publish pipelines (#504)

Adds an `executePublish` parameter to the publishing root pipelines and
threads it into the shared `OxidizerGitHub.Publish.yml` template
(ox-sdk).

**Why:** the cargo release dry-run in `publish_staging` fails when
multiple crates must be published in one run, because a dependent
crate's dry-run cannot resolve the not-yet-published version of an
earlier crate in topo order.

**Behavior:**
- `publish.yml` (Official): `executePublish` defaults to **true** ->
real publish (`execute: true`).
- `publish-testing.yml` (unofficial): defaults to **false** ->
`publish_staging` is skipped, so per-commit runs no longer hit the
broken dry-run. Set it true to exercise the publish path as a dry-run.

Requires the matching ox-sdk template change that adds the
`executePublish` parameter.

Author: martin-kolinek

.ado/pipelines/publish-testing.yml

@@ -15,6 +15,15 @@ parameters:
 - name: previousVersion
   type: string
   default: 'HEAD^'
+# Whether to perform the publish. Defaults to false on the unofficial
+# (Testing) pipeline so per-commit runs skip publishing entirely. Set it to
+# true to exercise the publish path as a dry-run (the template forces
+# `execute: false` for Testing); note that the cargo release dry-run can fail
+# when multiple crates must be published in one run.
+- name: executePublish
+  displayName: 'Publish crates (dry-run on this unofficial pipeline)'
+  type: boolean
+  default: false
 
 resources:
   repositories:
@@ -32,4 +41,5 @@ extends:
     validationOsList: ${{ parameters.validationOsList }}
     validationProfiles: ${{ parameters.validationProfiles }}
     previousVersion: ${{ parameters.previousVersion }}
-    pipelineType: 'Testing'
+    pipelineType: 'Testing'
+    executePublish: ${{ parameters.executePublish }}

.ado/pipelines/publish.yml

@@ -15,6 +15,12 @@ parameters:
 - name: previousVersion
   type: string
   default: 'HEAD^'
+# Whether to perform the publish. On the Official pipeline this defaults to
+# true so qualifying builds publish for real.
+- name: executePublish
+  displayName: 'Publish crates (real publish)'
+  type: boolean
+  default: true
 
 resources:
   repositories:
@@ -29,4 +35,5 @@ extends:
   parameters:
     validationOsList: ${{ parameters.validationOsList }}
     validationProfiles: ${{ parameters.validationProfiles }}
-    previousVersion: ${{ parameters.previousVersion }}
+    previousVersion: ${{ parameters.previousVersion }}
+    executePublish: ${{ parameters.executePublish }}