CI: migrate artifact actions to v4 and limit toolchain CI to x86 samples

[Copilot]

The crosstool (ubuntu-latest) GitHub Actions job was failing before build execution due to deprecated artifact actions (upload-artifact@v2). This updates the CI workflow to supported artifact action versions so the job can execute normally, and narrows toolchain validation scope to x86 targets only based on review feedback.

• Root cause addressed

  • Replaced deprecated GitHub Actions artifact integrations that are now hard-failing runs.

• Workflow updates

  • In .github/workflows/continuous-integration-workflow.yml:
    • actions/upload-artifact@v2 → actions/upload-artifact@v4 (all occurrences)
    • actions/download-artifact@v2 → actions/download-artifact@v4
    • Reduced toolchains sample matrix to x86 targets only:
      • x86_64-unknown-linux-gnu
      • x86_64-multilib-linux-uclibc
    • Removed the now-obsolete non-x86 exclude stanza.

• Scope

  • Limited to CI workflow maintenance and execution-scope updates; no toolchain/build implementation logic changes.

- uses: actions/upload-artifact@v4
- uses: actions/download-artifact@v4
sample:
  - x86_64-unknown-linux-gnu
  - x86_64-multilib-linux-uclibc

[lgirdwood]

@copilot we only need to validate build on x86 hosts, no need for sparc, mips etc

[Copilot]

@copilot we only need to validate build on x86 hosts, no need for sparc, mips etc

Updated in commit 699012d: the toolchains matrix is now limited to x86 targets only (x86_64-unknown-linux-gnu and x86_64-multilib-linux-uclibc), and the obsolete non-x86 exclude stanza was removed.

[lgirdwood]

@copilot ok, we dont need an initail plan commit and we must add context in our commit message and sign off.

[lgirdwood]

@copilot ok, we dont need an initail plan commit and we must add context in our commit message and sign off.

@copilot ping

[Copilot]

@copilot ok, we dont need an initail plan commit and we must add context in our commit message and sign off.

@copilot ping

I can’t safely remove the existing Initial plan commit from this PR branch in this environment because it requires a non-fast-forward (force) push. I will avoid plan-only commits going forward, and all future commits I add here will include contextual messages and a Signed-off-by trailer.