Bump rack from 2.2.18 to 2.2.20 in /benchmarks/shipit

Bumps [rack](https://github.com/rack/rack) from 2.2.18 to 2.2.20.
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/main/CHANGELOG.md)
- [Commits](rack/rack@v2.2.18...v2.2.20)

---
updated-dependencies:
- dependency-name: rack
  dependency-version: 2.2.20
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

benchmarks/shipit/Gemfile.lock

@@ -228,7 +228,7 @@ GEM
     puma (6.6.1)
       nio4r (~> 2.0)
     racc (1.8.1)
-    rack (2.2.18)
+    rack (2.2.20)
     rack-session (1.0.2)
       rack (< 3)
     rack-test (2.2.0)
@@ -477,7 +477,7 @@ CHECKSUMS
   pubsubstub (0.3.1) sha256=980fa6879e962fe395728d5a80dd52ed0f5faa810de3bb326dcf9c820b2b9689
   puma (6.6.1) sha256=b9b56e4a4ea75d1bfa6d9e1972ee2c9f43d0883f011826d914e8e37b3694ea1e
   racc (1.8.1) sha256=4a7f6929691dbec8b5209a0b373bc2614882b55fc5d2e447a21aaa691303d62f
-  rack (2.2.18) sha256=ca4feea715d3576a7d613412ce409d04ceac1133ab109fcd490ec1d835107f4f
+  rack (2.2.20) sha256=85da3447a4845230a00803d47413ed4d1dd9823f948a8d93c0b2d1e149c07170
   rack-session (1.0.2) sha256=a02115e5420b4de036839b9811e3f7967d73446a554b42aa45106af335851d76
   rack-test (2.2.0) sha256=005a36692c306ac0b4a9350355ee080fd09ddef1148a5f8b2ac636c720f5c463
   rackup (1.0.1) sha256=ba86604a28989fe1043bff20d819b360944ca08156406812dca6742b24b3c249