Bump psych from 5.3.1 to 5.4.0 (#44)

Bumps [psych](https://github.com/ruby/psych) from 5.3.1 to 5.4.0.
- [Release notes](https://github.com/ruby/psych/releases)
- [Commits](ruby/psych@v5.3.1...v5.4.0)

---
updated-dependencies:
- dependency-name: psych
  dependency-version: 5.4.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Gemfile

@@ -7,4 +7,4 @@ gem "sass-embedded", "1.100.0" # avoids deprecation errors
 gem "just-the-docs", "0.12.0" # pinned to the current release
 # gem "just-the-docs"        # always download the latest release
 
-gem "psych", "~> 5.3.1" # needed for retire.rb, as the default is too old
+gem "psych", "~> 5.4.0" # needed for retire.rb, as the default is too old

Gemfile.lock

@@ -71,7 +71,7 @@ GEM
     mercenary (0.4.0)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
-    psych (5.3.1)
+    psych (5.4.0)
       date
       stringio
     public_suffix (7.0.5)
@@ -99,7 +99,7 @@ PLATFORMS
 DEPENDENCIES
   jekyll (~> 4.4.1)
   just-the-docs (= 0.12.0)
-  psych (~> 5.3.1)
+  psych (~> 5.4.0)
   sass-embedded (= 1.100.0)
 
 BUNDLED WITH