Fix scheduled WASM extra-platforms job selection

[radekdoulik]

Problem

The scheduled runtime-extra-platforms pipeline includes this child template only for rolling builds, but since #133068 the child has repeated that check through variables.isRollingBuild. That ambient variable is unavailable during nested compile-time expansion, so it expands empty and the child selects the WASM-specific branches instead. Build 1610154 consequently omitted LibraryTestsCoreCLR_R2R and TestWasmReadyToRun while adding SingleThreaded_BuildOnly and non-extra browser CoreCLR jobs.

Fix

Use the explicit isExtraPlatformsBuild parameter to select the scheduled extra-platforms branch and its inverse for WASM-specific pipeline invocations. Use the explicit isWasmOnlyBuild parameter for WASI smoke alwaysRun behavior.

Validation

• parsed eng/pipelines/extra-platforms/runtime-extra-platforms-wasm.yml successfully as YAML
• authenticated Azure DevOps definition 154 preview against the PR merge ref includes LibraryTestsCoreCLR_R2R and TestWasmReadyToRun
• preview includes both browser smoke AOT jobs, both WASI AOT jobs, and both browser high-resource AOT jobs
• preview contains no SingleThreaded_BuildOnly references and no non-extra browser CoreCLR build-only jobs
• no pipeline run was queued; validation used the preview API only

/azp run runtime-extra-platforms cannot validate this scheduled path on a PR: PR runs set Build.Reason to PullRequest, which makes the root isRollingBuild gate omit the WASM child template entirely. The preview API expands definition 154 against the PR merge ref in the required rolling context without queuing a build. The next daily scheduled run after merge will provide the end-to-end confirmation.

Note

This pull request description was generated with GitHub Copilot.

[azure-pipelines]

Azure Pipelines:
Successfully started running 5 pipeline(s).
11 pipeline(s) were filtered out due to trigger conditions.
There may be pipelines that require an authorized user to comment /azp run to run.

[dotnet-policy-service]

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[Copilot]

Copilot review overview

🟢 Approval recommended

No blocking issues were identified; only a minor comment clarification remains.

Review effort: Lite
Findings: None

What changed in this PR

Fixes scheduled WASM extra-platform job selection by using explicit template parameters.

Changes:

• Uses isExtraPlatformsBuild for extra-platform branches.
• Uses isWasmOnlyBuild for WASI smoke behavior.
• Updates related pipeline conditions and comments.

File	Summary
eng/​pipelines/​extra-platforms/​runtime-extra-platforms-wasm.yml	Corrects parameter-based WASM job selection; one minor comment update was noted.

[radekdoulik]

/ba-g the failures are unrelated, pre-existing on main