fix(ci): drop invalid timeout-minutes from reusable-workflow calls (parse-dead) (#100)

## What

One or more jobs set a job-level `timeout-minutes:` on a job that calls
a reusable workflow via `uses:`. GitHub does not permit that key on a
`workflow_call` job, so it **rejected the file at parse time** — the
workflow failed instantly (`0s`) on every push and never ran a single
job.

## Fix

Remove the invalid caller-side `timeout-minutes:`. The standards
`*-reusable.yml` workflows already declare `timeout-minutes` on every
internal job, so the caller key was redundant as well as invalid.

## Verification

`actionlint` (real tool): no `timeout-minutes is not available` findings
remain.

## Context

Estate-wide shared-fate CI defect across 84 repos. Reference fix:
hyperpolymath/gitbot-fleet#374.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

Author: hyperpolymath

.github/workflows/mirror.yml

@@ -9,5 +9,4 @@ permissions:
 jobs:
   mirror:
     uses: hyperpolymath/standards/.github/workflows/mirror-reusable.yml@d135b05bfc647d0c0fbfedc7e80f37ea50f49236
-    timeout-minutes: 10
     secrets: inherit

.github/workflows/secret-scanner.yml

@@ -12,7 +12,6 @@ permissions:
 jobs:
   scan:
     uses: hyperpolymath/standards/.github/workflows/secret-scanner-reusable.yml@d135b05bfc647d0c0fbfedc7e80f37ea50f49236
-    timeout-minutes: 10
     secrets: inherit
   trufflehog:
     runs-on: ubuntu-latest