Pipelines: Adds main alongside master in CI trigger filters (#5812)

Adds `main` alongside `master` to the `trigger:`/`schedules:` branch
filters in every actively-triggered Azure Pipelines YAML, ahead of the
planned GitHub default-branch rename.

See [Software Freedom Conservancy: Renaming the default git
branch](https://sfconservancy.org/news/2020/jun/23/gitbranchname/).

This is **PR B of 3**:
- PR A (#5811) — docs / agents / scripts
- **PR B (this PR)** — adds `main` to CI trigger filters, transitional,
dual-branch
- PR C — drops `master` from CI trigger filters once `main` is verified

⚠️ **Do NOT merge until Monday's coordinated cutover.** This PR must be
merged immediately *before* the GitHub branch rename so CI continues
firing on both `master` (until rename) and `main` (immediately after
rename). Pipeline branch filters do **not** follow GitHub's
branch-rename redirects, which is why this transitional dual-include is
required.

### Files changed
| File | Change |
| --- | --- |
| `azure-pipelines.yml` | `pr.branches.include` adds `- main` |
| `azure-pipelines-functional.yml` | `pr.branches.include` adds `- main`
|
| `azure-pipelines-cron.yml` | `schedules[*].branches.include` adds `-
main` |
| `azure-pipelines-nightly.yml` | `schedules[*].branches.include` adds
`- main` |
| `azure-pipelines-rolling.yml` | Both `schedules[*].branches.include`
blocks add `- main` |

5 files, +6 lines.

### Out of scope
Pipelines using `trigger: none` (`azure-pipelines-official.yml`,
`-encryption-official.yml`, `-encryption-custom-official.yml`,
`-faultinjection.yml`, `-msdata-direct.yml`, `-msdata-aot.yml`,
`-ctl-publishing.yml`) configure their branches in the Azure DevOps UI
and will be updated as part of the cutover, not by a YAML change.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: NaluTripician

azure-pipelines-cron.yml

@@ -8,6 +8,7 @@ schedules:
   displayName: Cosmos Cron
   branches:
     include: 
+    - main
     - master
   always: true # Run always irrespective of changes
 

azure-pipelines-functional.yml

@@ -4,6 +4,7 @@ trigger: none
 pr:
   branches:
     include:
+    - main
     - master
     - releases/*
   paths:

azure-pipelines-nightly.yml

@@ -8,6 +8,7 @@ schedules:
   displayName: Cosmos Nightly 
   branches:
     include: 
+    - main
     - master
   always: true # whether to always run the pipeline or only if there have been source code changes since the last run. The default is false
 

azure-pipelines-rolling.yml

@@ -8,12 +8,14 @@ schedules:
   displayName: Cosmos Weekly Rolling
   branches:
     include: 
+    - main
     - master
   always: true # whether to always run the pipeline or only if there have been source code changes since the last run. The default is false
 - cron: "0 0/2 * * 0,6" # cron syntax https://learn.microsoft.com/en-us/azure/devops/pipelines/process/scheduled-triggers?view=azure-devops&tabs=yaml#cron-syntax
   displayName: Cosmos Weekly Rolling
   branches:
     include: 
+    - main
     - master
   always: true # whether to always run the pipeline or only if there have been source code changes since the last run. The default is false
 

azure-pipelines.yml

@@ -4,6 +4,7 @@ trigger: none
 pr:
   branches:
     include:
+    - main
     - master
     - releases/*
   paths: