Bump rack from 2.2.12 to 2.2.13 in /tech-docs in the bundler group (#735)

Bumps the bundler group in /tech-docs with 1 update: [rack](https://github.com/rack/rack).


Updates `rack` from 2.2.12 to 2.2.13
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/main/CHANGELOG.md)
- [Commits](rack/rack@v2.2.12...v2.2.13)

---
updated-dependencies:
- dependency-name: rack
  dependency-type: indirect
  dependency-group: bundler
...

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Author: dependabot[bot]

tech-docs/Gemfile.lock

@@ -160,7 +160,7 @@ GEM
     parslet (2.0.0)
     public_suffix (6.0.1)
     racc (1.8.1)
-    rack (2.2.12)
+    rack (2.2.13)
     rack-livereload (0.3.17)
       rack
     rake (13.2.1)