Wrong test jar looked up for infinispan protostream

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Package ecosystem

Maven

### Package manager version

_No response_

### Language version

_No response_

### Manifest location and content before the Dependabot update

_No response_

### dependabot.yml content

https://github.com/apache/camel/blob/main/.github/dependabot.yml

### Updated dependency

_No response_

### What you expected to see, versus what you actually saw

there are several 404 because it is searching for a test jar like protostream-6.0.6.test-jar but what is available is [protostream-6.0.6-tests.jar](https://repo1.maven.org/maven2/org/infinispan/protostream/protostream/6.0.6/protostream-6.0.6-tests.jar)

and with version 5.x: protostream-5.0.15.Final.test-jar but waht is available is [protostream-5.0.15.Final-tests.jar](https://repo1.maven.org/maven2/org/infinispan/protostream/protostream/5.0.15.Final/protostream-5.0.15.Final-tests.jar)

it consequently 1'20" just to do a bunch of 404

### Native package manager behavior

_No response_

### Images of the diff or a link to the PR, issue, or logs

```
2026-04-16T07:07:05.7067526Z updater | 2026/04/16 07:07:05 INFO Checking if org.infinispan.protostream:protostream 6.0.2 needs updating
2026-04-16T07:07:05.8794483Z proxy | 2026/04/16 07:07:05 [536] GET https://repo1.maven.org:443/maven2/org/apache/apache/37/apache-37.pom
2026-04-16T07:07:05.8796314Z 2026/04/16 07:07:05 [536] 200 https://repo1.maven.org:443/maven2/org/apache/apache/37/apache-37.pom (cached)
2026-04-16T07:07:05.9964072Z proxy | 2026/04/16 07:07:05 [538] GET https://repo1.maven.org:443/maven2/org/infinispan/protostream/protostream/maven-metadata.xml
2026-04-16T07:07:06.0116455Z proxy | 2026/04/16 07:07:06 [538] 200 https://repo1.maven.org:443/maven2/org/infinispan/protostream/protostream/maven-metadata.xml
2026-04-16T07:07:06.1283167Z proxy | 2026/04/16 07:07:06 [540] GET https://repo1.maven.org:443/maven2/org/infinispan/protostream/protostream
2026-04-16T07:07:06.2376775Z proxy | 2026/04/16 07:07:06 [540] 302 https://repo1.maven.org:443/maven2/org/infinispan/protostream/protostream
2026-04-16T07:07:06.3344514Z proxy | 2026/04/16 07:07:06 [542] GET https://repo1.maven.org:443/maven2/org/infinispan/protostream/protostream/
2026-04-16T07:07:06.3508796Z proxy | 2026/04/16 07:07:06 [542] 200 https://repo1.maven.org:443/maven2/org/infinispan/protostream/protostream/
2026-04-16T07:07:06.3879809Z updater | 2026/04/16 07:07:06 INFO Filtered out 71 pre-release versions
2026-04-16T07:07:06.3934811Z updater | 2026/04/16 07:07:06 INFO Filtered out 20 non-2 classifier versions
2026-04-16T07:07:06.4803714Z proxy | 2026/04/16 07:07:06 [544] HEAD https://repo1.maven.org:443/maven2/org/infinispan/protostream/protostream/15.0.13.Final/protostream-15.0.13.Final.test-jar
2026-04-16T07:07:06.6404483Z proxy | 2026/04/16 07:07:06 [544] 404 https://repo1.maven.org:443/maven2/org/infinispan/protostream/protostream/15.0.13.Final/protostream-15.0.13.Final.test-jar
2026-04-16T07:07:06.6918202Z proxy | 2026/04/16 07:07:06 Posting metrics to remote API endpoint
2026-04-16T07:07:06.7312487Z proxy | 2026/04/16 07:07:06 [546] HEAD https://repo1.maven.org:443/maven2/org/infinispan/protostream/protostream/6.0.6/protostream-6.0.6.test-jar
2026-04-16T07:07:06.7322096Z proxy | 2026/04/16 07:07:06 Successfully posted metrics data via api client
2026-04-16T07:07:06.8703744Z proxy | 2026/04/16 07:07:06 [546] 404 https://repo1.maven.org:443/maven2/org/infinispan/protostream/protostream/6.0.6/protostream-6.0.6.test-jar
2026-04-16T07:07:06.9674738Z proxy | 2026/04/16 07:07:06 [548] HEAD https://repo1.maven.org:443/maven2/org/infinispan/protostream/protostream/6.0.5/protostream-6.0.5.test-jar
2026-04-16T07:07:07.1128373Z proxy | 2026/04/16 07:07:07 [548] 404 https://repo1.maven.org:443/maven2/org/infinispan/protostream/protostream/6.0.5/protostream-6.0.5.test-jar
2026-04-16T07:07:07.2113635Z proxy | 2026/04/16 07:07:07 [550] HEAD https://repo1.maven.org:443/maven2/org/infinispan/protostream/protostream/6.0.4/protostream-6.0.4.test-jar
2026-04-16T07:07:07.3526568Z proxy | 2026/04/16 07:07:07 [550] 404 https://repo1.maven.org:443/maven2/org/infinispan/protostream/protostream/6.0.4/protostream-6.0.4.test-jar
2026-04-16T07:07:07.4483075Z proxy | 2026/04/16 07:07:07 [552] HEAD https://repo1.maven.org:443/maven2/org/infinispan/protostream/protostream/6.0.3/protostream-6.0.3.test-jar
2026-04-16T07:07:07.6011106Z proxy | 2026/04/16 07:07:07 [552] 404 https://repo1.maven.org:443/maven2/org/infinispan/protostream/protostream/6.0.3/protostream-6.0.3.test-jar
```

```
2026-04-16T07:07:08.4275108Z proxy | 2026/04/16 07:07:08 [560] HEAD https://repo1.maven.org:443/maven2/org/infinispan/protostream/protostream/5.0.15.Final/protostream-5.0.15.Final.test-jar
2026-04-16T07:07:08.5485441Z proxy | 2026/04/16 07:07:08 [560] 404 https://repo1.maven.org:443/maven2/org/infinispan/protostream/protostream/5.0.15.Final/protostream-5.0.15.Final.test-jar
```

### Smallest manifest that reproduces the issue

_No response_

Start with the .github/dependabot.yml configuration and the Maven update logs showing requests for protostream-*.test-jar. Trace how the Maven updater derives test-jar filenames and compare them with the linked Maven Central artifacts ending in -tests.jar. Done means the updater finds the available test artifacts without the repeated 404 lookups.

Written by the indexing model from the issue text.