Bump org.webjars.npm:bootstrap from 5.3.5 to 5.3.6 in /perf-tests

Bumps [org.webjars.npm:bootstrap](https://github.com/twbs/bootstrap) from 5.3.5 to 5.3.6.
- [Release notes](https://github.com/twbs/bootstrap/releases)
- [Commits](twbs/bootstrap@v5.3.5...v5.3.6)

---
updated-dependencies:
- dependency-name: org.webjars.npm:bootstrap
  dependency-version: 5.3.6
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

perf-tests/build.gradle

@@ -15,7 +15,7 @@ repositories {
 }
 
 ext.webjarsFontawesomeVersion = "4.7.0"
-ext.webjarsBootstrapVersion = "5.3.5"
+ext.webjarsBootstrapVersion = "5.3.7"
 
 dependencies {
   implementation 'org.springframework.boot:spring-boot-starter-cache'