feat(tests): Add Java version check for bats tests

- Introduced a `_require_java_version` helper function in
  `agent/test/helper.bash` to allow bats tests to specify a minimum
  required Java version. Tests will be skipped if the current Java
  version is below the requirement.
- Applied the Java 11 requirement to the `gretty-tomcat` bats tests to
  ensure they run in a compatible environment.

Author: dividedmind

agent/test/gretty-tomcat/gretty-tomcat.bats

@@ -3,6 +3,8 @@
 load '../helper'
 
 setup_file() {
+  _require_java_version 11
+
   mkdir -p build/log
 
   export LOG="$(getcwd)/build/log/gretty-tomcat.log"

agent/test/helper.bash

@@ -14,6 +14,13 @@ export JAVA_VERSION
 export JAVA_OUTPUT_OPTIONS="-Xshare:off"
 
 
+_require_java_version() {
+  local required_version=$1
+  if [[ "$(echo -e "$required_version\n$JAVA_VERSION" | sort -V | head -n1)" != "$required_version" ]]; then
+    skip "Java version $required_version or higher is required (current: $JAVA_VERSION)"
+  fi
+}
+
 _curl() {
   curl -sfH 'Accept: application/json,*/*' "${@}"
 }