[Repo Assist] ci: align action versions in docs workflow and add NuGet cache to publish workflow

[github-actions]

🤖 This is an automated pull request from Repo Assist.

Summary

Two small CI consistency fixes:

docs.yaml — action versions were behind those used in every other workflow:

• actions/checkout@v4 → actions/checkout@v6
• actions/cache@v4 → actions/cache@v5

publish.yaml — was the only workflow without a NuGet package cache step:

• Added actions/cache@v5 step (same pattern as build.yaml, test.yaml, main.yaml) to avoid re-downloading packages on every publish run

Why

build.yaml, test.yaml, and main.yaml all use actions/checkout@v6 and actions/cache@v5. docs.yaml was left at @v4/@v4. This matters mainly to avoid version drift and ensure all workflows benefit from the latest checkout/cache improvements. The publish workflow was also missing the cache entirely, causing unnecessary NuGet downloads on every push to main.

Test Status

No application code changed; workflow YAML changes only. The docs and publish workflows are not easily testable in a PR, but the changes are minimal (version bumps + adding an established cache pattern) and match the patterns already working in all other workflows.

Generated by Repo Assist · ◷

To install this agentic workflow, run

gh aw add githubnext/agentics/workflows/repo-assist.md@346204513ecfa08b81566450d7d599556807389f

Generated by Repo Assist · ◷

To install this agentic workflow, run

gh aw add githubnext/agentics/workflows/repo-assist.md@d1d884596e62351dd652ae78465885dd32f0dd7d

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Warning

🛡️ Protected Files — Push Permission Denied

This was originally intended as a pull request, but the patch modifies protected files: .github/workflows/docs.yaml, .github/workflows/publish.yaml.

The push was rejected because GitHub Actions does not have workflows permission to push these changes, and is never allowed to make such changes, or other authorization being used does not have this permission. A human must create the pull request manually.

To create a pull request with the changes:

# Download the patch from the workflow run
gh run download 23392869208 -n agent-artifacts -D /tmp/agent-artifacts-23392869208

# Create a new branch
git checkout -b repo-assist/eng-update-docs-workflow-actions-20260322-31f8718cb30c55f6 main

# Apply the patch (--3way handles cross-repo patches)
git am --3way /tmp/agent-artifacts-23392869208/aw-repo-assist-eng-update-docs-workflow-actions-20260322.patch

# Push the branch and create the pull request
git push origin repo-assist/eng-update-docs-workflow-actions-20260322-31f8718cb30c55f6
gh pr create --title '[Repo Assist] ci: align action versions in docs workflow and add NuGet cache to publish workflow' --base main --head repo-assist/eng-update-docs-workflow-actions-20260322-31f8718cb30c55f6 --repo fsprojects/FSharp.Control.TaskSeq