Upgrade rest-assured 4.5.1 -> 5.5.2

[devin-ai-integration]

Summary

Bumps all four io.rest-assured test artifacts (rest-assured, json-path, xml-path, spring-mock-mvc) from 4.5.1 to 5.5.2, the latest release, and pins them through a single restAssuredVersion ext property so they can't drift apart:

+ext['restAssuredVersion'] = '5.5.2'
-testImplementation 'io.rest-assured:rest-assured:4.5.1'
+testImplementation "io.rest-assured:rest-assured:${restAssuredVersion}"

No test code changes were needed. The 4.x -> 5.x jump is a Groovy 3 -> Groovy 4 migration under the hood (org.codehaus.groovy -> org.apache.groovy, a different Maven group, so it doesn't collide with the Groovy 3 that the Boot 2.6.3 BOM manages for spring-boot-starter-test). The RestAssuredMockMvc surface used across src/test/java/io/spring/api/* (given(), standaloneSetup, RestAssuredMockMvc.mockMvc) is unchanged, so all 8 API test classes compile and pass untouched.

spring-mock-mvc 5.5.2 still builds against Spring 5 / javax.servlet (its POM sets spring.version=5.1.13.RELEASE), so it remains compatible with the current Spring Boot 2.6.3 / Java 11 baseline — no Boot 3 or jakarta prerequisite.

Verification

Run on JDK 11 (matching CI):

• ./gradlew clean test -x jacocoTestCoverageVerification — 68 tests, 0 failures
• ./gradlew spotlessCheck — clean

Note: jacocoTestCoverageVerification fails at 0.33 instruction coverage against the 0.80 rule, but that is pre-existing — main produces the identical 0.33 figure, and CI already runs with -x jacocoTestCoverageVerification.

Also refreshed the dependency baseline row in .agents/skills/java-engineering-excellence/SKILL.md, which still listed rest-assured at 4.5.1.

Link to Devin session: https://partner-workshops.devinenterprise.com/sessions/89d7668e4a0f41df961b621ba08c07f1
Requested by: @mbatchelor81

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR. Add '(aside)' to your comment to have me ignore it.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment, CI, and merge conflict monitoring