Remove auto dependbot

[jexShain]

Summary

Describe the problem and fix in 2–5 bullets:

• Problem: The repository had an unused dependabot configuration file that was no longer required.
• Why it matters: Removing unused or obsolete files reduces repository clutter and improves maintainability.
• What changed: Deleted the dependabot configuration file from the repository.
• What did NOT change (scope boundary): No changes were made to CI/CD pipelines, dependency management workflows, or other automation tools.

Change Type (select all)

• Bug fix
• Feature
• Refactor
• Docs
• Security hardening
• Chore/infra

Scope (select all touched areas)

• Core shell / PTY (src/aish/shell*.py, src/aish/shell_enhanced/)
• AI agent / LLM (src/aish/agents.py, src/aish/llm.py, src/aish/prompts.py)
• Skills / Tools (src/aish/skills/, src/aish/tools/, debian/skills/)
• Security / Risk assessment (src/aish/security/)
• Sandbox (src/aish/sandboxd.py, src/aish/security/sandbox*.py)
• Configuration / Wizard (src/aish/config.py, src/aish/wizard/)
• CLI / Interface (src/aish/cli.py, src/aish/help_manager.py)
• I18N (src/aish/i18n/)
• Observability (src/aish/logging_utils.py, src/aish/session_store.py)
• Packaging / Installation (aish.spec, build.sh, debian/)
• CI/CD / Infra (.github/)
• Documentation (docs/, *.md)

Linked Issue/PR

• Related: None

User-visible / Behavior Changes

List user-visible changes (including defaults/config).
If none, write None.

• None.

Security Impact (required)

• New security risk levels or policy changes? (No)
• Secrets/tokens handling changed? (No)
• New/changed network calls (LLM providers)? (No)
• Command execution surface changed? (No)
• Sandbox isolation changed? (No)
• Data access scope changed? (No)
• If any Yes, explain risk + mitigation:

Repro + Verification

Environment

• OS: Any
• Python version: N/A
• Model/provider tested: N/A
• Install method (deb/built from source/uv run): N/A

Steps

1. Navigate to the repository root.
2. Verify that the dependabot file is no longer present in the .github directory.

Expected

• No dependabot file is found under .github.

Actual

Evidence

Attach at least one:

• Failing test/log before + passing after
• Test output (pytest)
• Log snippets (~/.config/aish/logs/aish.log)
• Screenshot/recording

Human Verification (required)

What you personally verified (not just CI), and how:

• Verified scenarios: Manually checked the absence of the dependabot file.
• Edge cases checked: None, as only a file deletion occurred.
• What you did not verify: Any workflows dependent on this file, since it is unused.

Compatibility / Migration

• Backward compatible? (Yes)
• Config changes? (No)
• Security policy changes? (No)

Failure Recovery (if this breaks)

• How to disable/revert this change quickly: Restore the dependabot file to its original location.
• Files/config to restore: .github/dependabot.yml
• Known bad symptoms reviewers should watch for: None

Risks and Mitigations

List only real risks for this PR. Add/remove entries as needed. If none, write None.

• Risk: None
  • Mitigation: N/A