Update Java dependencies

The RPM spec has been updated to use Java 21 on Fedora 40 or
later and Java 17 on other platforms.

The Dockerfile has been modified to remove any Java packages
pulled by the existing JSS package to ensure that the build
will be done using the correct Java version.

Dockerfile

@@ -26,7 +26,7 @@ RUN if [ -n "$COPR_REPO" ]; then dnf copr enable -y $COPR_REPO; fi
 
 # Install JSS runtime dependencies
 RUN dnf install -y dogtag-jss \
-    && dnf remove -y dogtag-* --noautoremove \
+    && rpm -e --nodeps $(rpm -qa | grep -E "^java-|^dogtag-") \
     && dnf clean all \
     && rm -rf /var/cache/dnf
 

jss.spec

@@ -55,10 +55,28 @@ ExcludeArch: i686
 # Java
 ################################################################################
 
+%if 0%{?rhel}
+
 %define java_devel java-17-openjdk-devel
 %define java_headless java-17-openjdk-headless
 %define java_home %{_jvmdir}/jre-17-openjdk
 
+%else
+
+# Use Java 21 on Fedora 40+
+%global java_devel java-devel >= 1:17
+%global java_headless java-headless >= 1:17
+
+# Don't use find since it might not work well with local builds.
+#   find {_jvmdir} -maxdepth 1 | grep "jre-[0-9]\+$"
+%global java_home %(
+   source /usr/share/java-utils/java-functions;
+   _prefer_jre=true;
+   set_jvm;
+   echo $JAVA_HOME)
+
+%endif
+
 ################################################################################
 # Build Options
 ################################################################################