upstream: Review Julia through 81093121d4e6

[github-actions]

Upstream Julia 53f4db20b59cf7620a364b3b9a419f4a8eb0bdcd → 81093121d4e6cf469154d977e2ecd6b7488ea0de.

The reviewer merged the batch only in its temporary checkout. This published PR contains the report alone. The resolved source integration, matching Pkg controls, and batching fix are in #18; this report is closed as superseded. The checkpoint advances only when the tested replacement merges.

Draft for human review. Automatic merging is disabled.

REPORT ONLY: upstream code and the integrated checkpoint are unchanged. Resolve the concerns before integrating.

Review record: contrib/upstream-sync/reports/81093121d4e6cf469154d977e2ecd6b7488ea0de.json.

Incoming commits:

• 749bc4e20490bac5bb01f69bd433d8dc8a6b36e3 — precompilation: skip dependents of failed packages, add force options (change 63122)
• 81093121d4e6cf469154d977e2ecd6b7488ea0de — doc: cover the TTFX jobs and artifact downloads in the buildkite-logs skill (change 63243)

Unresolved concerns:

• 8109312 modifies doc/src/devdocs/agents/skills/buildkite-logs/SKILL.md, a protected agent-instruction path. This requires manual handling and prevents a proposal.
• base/precompilation.jl advertises pkg> precompile --noskip, but stdlib/Pkg/src/REPLMode/command_declarations.jl does not declare that option and stdlib/Pkg/src/API.jl does not forward the new controls to Base. The missing Pkg CLI/API follow-up is outside the pinned commit list and must be resolved by a human.
• No builds or runtime tests were run; this job has no built Joolia and is not the verification job.

Merge integrated batches with a merge commit, never squash/rebase, to preserve the upstream ancestry.
Passing CI covers only contrib/ci/coverage.json; it does not certify the entire port.