Add empty stdout fallback for az version in AzureCLIV3 and fix vulnerabilities

[v-schhabra]

Context

The UseAzVersion feature flag enables running az version instead of az --version. An edge case was discovered where az version can succeed (exit code 0, no stderr) but return empty/null stdout, causing downstream version parsing to fail.

#21512
#21952

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Task Name

AzureCLIV3

Description

• Added empty stdout fallback for az version command — When the UseAzVersion feature flag is ON, added two additional checks to the fallback condition. If az version returns empty/null stdout, the task now gracefully falls back to az --version instead of failing during version parsing.
• Updated azure-pipelines-tasks-artifacts-common from ^2.262.0 to ^2.270.0

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Risk Assessment (Low / Medium / High)

Low
The code change is behind the UseAzVersion feature flag and only widens fallback conditions — existing path is unchanged.

Change Behind Feature Flag (Yes / No)

Yes
The code change is gated behind the UseAzVersion pipeline feature flag. When the flag is OFF, the new conditions are never evaluated.

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Tech Design / Approach

No

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Documentation Changes Required (Yes/No)

No

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Unit Tests Added or Updated (Yes / No)

No

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Additional Testing Performed

Uploaded task to private org using tfx-cli and did testing.

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Logging Added/Updated (Yes/No)

No

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Telemetry Added/Updated (Yes/No)

No

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Rollback Scenario and Process (Yes/No)

In case of any issues we can disable the FF.

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Checklist

• Related issue linked (if applicable)
• Task version was bumped — see versioning guide
• Verified the task behaves as expected

[azure-pipelines]

Azure Pipelines:
Successfully started running 3 pipeline(s).

[azure-pipelines]

Azure Pipelines:
Successfully started running 3 pipeline(s).

[azure-pipelines]

Azure Pipelines:
Successfully started running 3 pipeline(s).

[azure-pipelines]

Azure Pipelines:
Successfully started running 3 pipeline(s).