Pin some version ranges for dependabot [skip ci]

Author: bbottema

.github/dependabot.yml

@@ -16,7 +16,7 @@ updates:
         update-types:
           - "version-update:semver-minor"
           - "version-update:semver-major"
-      - dependency-name: "org.springframework.boot:spring-boot-dependencies"
+      - dependency-name: "org.springframework.boot:*"
         update-types:
           - "version-update:semver-minor"
           - "version-update:semver-major"