Improve missing metadata reporting for newer repository releases

[jormundur00]

Closes #947

Summary

This PR improves listLibrariesMissingMetadata reporting so Native Build Tools distinguishes between:

• dependencies that are genuinely missing from the reachability metadata repository
• dependencies that are already covered by a newer official metadata repository release than the one currently configured or bundled

Instead of treating both cases as "missing" and offering or creating support requests for all of them, the command now performs a second lookup against the latest official reachability metadata release when the configured repository does not cover a dependency.

If the dependency is found there, the report:

• classifies it separately as supported_in_newer_metadata_repository
• does not create or suggest a GitHub issue for that dependency
• tells the user to upgrade the metadata repository version or Native Build Tools

What Changed

• added a second-pass lookup in MissingMetadataCommandSupport against the latest official GraalVM reachability metadata release
• introduced a dedicated supported_in_newer_metadata_repository result status in the JSON report
• updated console rendering to show dependencies covered by a newer release in a separate section
• kept issue creation limited to dependencies that remain uncovered after both checks
• added focused tests covering the newer-release path and the no-issue-creation behavior
• updated the functional spec for missing metadata reporting and repository coverage semantics
• replaced the list-libraries-missing-metadata schema v1.0.0 with v1.1.0
• updated Gradle and Maven docs to reference the v1.1.0 schema

Why

Today, users running an older Native Build Tools build or an older metadata repository can end up opening issues against oracle/graalvm-reachability-metadata for libraries that are already covered on the repository, just not in the version they are currently consuming.

This change keeps the output actionable for those users while avoiding false-positive support requests.

Example Output

Example console output showing the new section in context when a dependency is not covered by the configured metadata repository but is covered by a newer release:

[INFO] Dependencies needing attention: 6 of 18 scanned (1 covered in a newer metadata repository release).

Covered in a newer metadata repository release (update metadata repository or Native Build Tools):
  - org.springframework.boot:spring-boot-starter-webmvc:4.1.0 -> supported in 1.0.3
      update metadata repository to 1.0.3 or upgrade Native Build Tools

To request support for the remaining 5 libraries automatically, re-run with createIssues=true:

    ./mvnw native:list-libraries-missing-metadata -DcreateIssues=true -DgithubToken=<token>

  Token sources tried in order:
    -DgithubToken=...  ->  $GITHUB_TOKEN  ->  $GH_TOKEN  ->  `gh auth token`

Or request support manually, one library at a time:
  - org.springframework.boot:spring-boot-starter-cache:3.5.6      -> request support [1]
  - org.springframework.boot:spring-boot-starter-thymeleaf:3.5.6  -> request support [2]
  - org.webjars.npm:bootstrap:5.3.8                               -> request support [3]

In that case, the dependency is surfaced to the user, but it is excluded from issue creation and from the manual support-request list.

Validation

• grund check
• ./gradlew --no-daemon --console=plain :graalvm-reachability-metadata:test --tests org.graalvm.reachability.MissingMetadataCommandSupportTest