feat: add new configuration files for Apt, Apk, Java, and Yum

Signed-off-by: d9pouces <github@19pouces.net>

tests/dockerfiles/repos/java-repo.Dockerfile

@@ -0,0 +1,14 @@
+# Minimal Maven-compatible repository serving one hand-built jar over plain
+# HTTP, used by tox-docker to exercise the `java` module integration test
+# (tests/configs/Java.yaml.tmpl, tests/dockerfiles/Java.Dockerfile).
+#
+# Built by tox-docker, whose build context is this directory (not the repo
+# root) - every COPY source below must live under tests/dockerfiles/repos/.
+FROM python:3.13-slim AS jarbuild
+COPY build_test_jar.py /build_test_jar.py
+RUN python3 /build_test_jar.py
+
+FROM nginx:alpine
+COPY --from=jarbuild /srv /srv
+COPY java-repo.nginx.conf /etc/nginx/conf.d/default.conf
+EXPOSE 8443