fix(cluster): install openjdk-11 for offline install

since we bumped the jre used by scylla-jmx from openjdk-8
to openjdk-11, and we started to check for jre-11. despite
that scylla-jmx still works with jre-8, jre-11 is the
recommended JRE for running scylla-jmx, let's use openjdk-11
for testing offline installation.

please note, scylladb/scylla-jmx#198
was also created to address this issue. but in the long
run, this fix is a better one. as it's always desirable to
use a better supported jre in testing.

Refs scylladb/scylla-jmx#127
Fixes scylladb/scylladb#13414
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

sdcm/cluster.py

@@ -2000,18 +2000,18 @@ def offline_install_scylla(self, unified_package, nonroot):
         else:
             additional_pkgs += ' python2'
 
-        # Offline install does't provide openjdk-8, it has to be installed in advance
+        # Offline install does't provide openjdk-11, it has to be installed in advance
         # https://github.com/scylladb/scylla-jmx/issues/127
         if self.is_rhel_like():
-            self.remoter.run(f'sudo yum install -y java-1.8.0-openjdk {additional_pkgs}')
+            self.remoter.run(f'sudo yum install -y java-11-openjdk-headless {additional_pkgs}')
         elif self.distro.is_sles:
             raise Exception("Offline install on SLES isn't supported")
         elif self.distro.is_debian10 or self.distro.is_debian11:
             self.remoter.run(f'sudo apt-get install -y openjdk-11-jre-headless {additional_pkgs}')
         else:
-            self.remoter.run(f'sudo apt-get install -y openjdk-8-jre-headless {additional_pkgs}')
+            self.remoter.run(f'sudo apt-get install -y openjdk-11-jre-headless {additional_pkgs}')
             self.remoter.run('sudo update-java-alternatives --jre-headless '
-                             '-s java-1.8.0-openjdk-${dpkg-architecture -q DEB_BUILD_ARCH}')
+                             '-s java-1.11.0-openjdk-${dpkg-architecture -q DEB_BUILD_ARCH}')
 
         package_version_cmds_v2 = dedent("""
             tar -xzO --wildcards -f ./unified_package.tar.gz .relocatable_package_version