remove SQL migration tool

[ghubertpalo]

Content

This PR removes migration tools (and associated libraries) from JSON → SQLite3.

Pre-submit checklist

• Branch
  • Tests are provided (if possible)
  • Commit sequence broadly makes sense
  • Key commits have useful messages
• PR
  • No clippy warnings in the CI
  • Self-reviewed the diff
  • Useful pull request description
  • Reviewer requested
• Documentation
  • Update README file (if relevant)
  • Update documentation website (if relevant)
  • Add dev blog post (if relevant)

Issue(s)

Closes #539

[github-actions]

Unit Test Results

    7 files  ±0    22 suites   - 2   2m 3s ⏱️ -3s
334 tests  - 6  334 ✔️  - 6  0 💤 ±0  0 ❌ ±0 
335 runs   - 6  335 ✔️  - 6  0 💤 ±0  0 ❌ ±0 

Results for commit 54c2a3f. ± Comparison against base commit 978f15f.

This pull request removes 6 tests.

src/store/adapter_migration.rs - store::adapter_migration ‑ AdapterMigration (line 79)
store::adapter_migration::tests ‑ test_check_different_values
store::adapter_migration::tests ‑ test_check_key_not_exist
store::adapter_migration::tests ‑ test_check_keys_unaligned
store::adapter_migration::tests ‑ test_check_ok
store::adapter_migration::tests ‑ test_migration

♻️ This comment has been updated with latest results.

[jpraynaud]

LGTM 👍