Use metrics-base ant task to fetch metrics-lib.

Implements part of #31649.

.gitlab-ci.yml

 variables:
   GIT_STRATEGY: clone
-  METRICS_LIB_VERSION: "2.6.2"
   JAVA_TOOL_OPTIONS: "-Dfile.encoding=UTF-8"
 
 stages:
@@ -15,11 +14,7 @@ test:
   - git submodule init
   - git submodule update
   - mkdir lib
-  - mkdir tmp
-  - pushd tmp
-  - curl https://dist.torproject.org/metrics-lib/$METRICS_LIB_VERSION/metrics-lib-$METRICS_LIB_VERSION.tar.gz | tar xzf -
-  - popd
-  - mv tmp/metrics-lib-$METRICS_LIB_VERSION/generated/dist/metrics-lib-$METRICS_LIB_VERSION-thin.jar lib
+  - ant fetch-metrics-lib
   - ant -lib /usr/share/java resolve
   - ant test
   - ant checks

build @ 07c2a00c

-Subproject commit 75cda35ba7375ab0f5b12fa214620c3a29917097
+Subproject commit 07c2a00c27f0d536223f8b5a61fc91e60eb524d4