ISA95 Smoke Test: Convert to scheduled builds rather than every commit (

#5702)

For ISA95 Smoke Tests, removing the commit trigger in favor of scheduled builds. Will port this change to master also.

Waiting for this run before merge:
https://dev.azure.com/msazure/One/_build/results?buildId=47888354&view=results

# Azure IoT Edge PR checklist:

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### General Guidelines and Best Practices
- [x] I have read the [contribution guidelines](https://github.com/azure/iotedge#contributing).
- [x] Title of the pull request is clear and informative.
- [x] Description of the pull request includes a concise summary of the enhancement or bug fix.

### Testing Guidelines
- [ ] Pull request includes test coverage for the included changes.
- Description of the pull request includes 
	- [ ] concise summary of tests added/modified
	- [ ] local testing done.  

### Draft PRs
- Open the PR in `Draft` mode if it is:
	- Work in progress or not intended to be merged.
	- Encountering multiple pipeline failures and working on fixes.

_Note: We use the kodiakhq bot to merge PRs once the necessary checks and approvals are in place. When it merges a PR, kodiakhq converts the PR title to the commit title, PR description to the commit description, and squashes all the commits in the PR to a single commit. The net effect is that entire PR becomes a single commit. Please follow the best practices mentioned [here](https://chris.beams.io/posts/git-commit/#:~:text=The%20seven%20rules%20of%20a%20great%20Git%20commit,what%20and%20why%20vs.%20how%20For%20example%3A%20) for the PR title and description_

builds/e2e/isa-95-smoke-test.yaml

@@ -1,6 +1,21 @@
 trigger: none
 pr: none
 
+# Test schedule the same between master and release/1.2, but offset 12 hours.
+schedules:
+- cron: "0 0 * * *"
+  displayName: Daily build master
+  branches:
+    include:
+    - master
+  always: true
+- cron: "0 12 * * *"
+  displayName: Daily build release/1.2
+  branches:
+    include:
+    - release/1.2
+  always: true
+
 variables:
   NugetSecurityAnalysisWarningLevel: warn
   itProxy: http://10.16.8.4:3128
@@ -12,17 +27,9 @@ resources:
   - pipeline: images
     source: 'Azure-IoT-Edge-Core Build Images'
     branch: 'release/1.2'
-    trigger:
-      branches:
-      - master
-      - release/*
   - pipeline: packages
     source: 'Azure-IoT-Edge-Core Edgelet Packages'
     branch: 'release/1.2'
-    trigger:
-      branches:
-      - master
-      - release/*
 
 stages:
 - stage: LockAgents