ci(docker): self-trigger on workflow file changes

[brunobuddy]

Summary

Tiny follow-up to #1549. The Docker workflow's pull_request path filter didn't include .github/workflows/docker.yml itself, so PRs that only touch the workflow — like #1549 did — don't actually exercise the Docker validate job. I only caught this after #1549 merged and realised the new amd64/arm64 matrix had never been run against a real PR.

Adding the workflow file to its own path filter is standard practice and makes future workflow edits self-validate.

Test plan

• YAML still parses
• This very PR should now show Build (validate, amd64) and Build (validate, arm64) in the checks — that's the first real signal that the native-runner matrix shape from ci(docker): build arm64 on native runners, drop QEMU emulation #1549 actually works. If either check fails, that's the signal to iterate on ci(docker): build arm64 on native runners, drop QEMU emulation #1549's shape.

---

Summary by cubic

Include .github/workflows/docker.yml in the Docker workflow’s pull_request.paths so edits to the workflow trigger the Docker validate job (amd64/arm64). This ensures workflow changes self-validate instead of silently skipping the matrix.

^{Written for commit 06aef89. Summary will update on new commits.}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.93%. Comparing base (e1e07e3) to head (06aef89).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1550   +/-   ##
=======================================
  Coverage   97.93%   97.93%           
=======================================
  Files         118      118           
  Lines        8581     8581           
  Branches     3230     3230           
=======================================
  Hits         8404     8404           
  Misses        175      175           
  Partials        2        2           

Flag	Coverage Δ
frontend	97.93% <ø> (ø)
shared	100.00% <ø> (ø)

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