[CI Docker] Update base images and OpenJDK version

[ylca0]

[CI Dockerfile] Update base images & openjdk version.

1. Update JDK version to 21 for Ghidra 11.4.
2. Update almalinux version to 10.1:minimal for decompiler of Ghidra 11.4.

Error output:

/root/.config/ghidra/ghidra_11.4_F331B5BBEA-202504251242/jar.resource.copied.files/decompile: /lib64/libc.so.6: version `GLIBC_2.38' not found (required by /root/.config/ghidra/ghidra_11.4_F331B5BBEA-202504251242/jar.resource.copied.files/decompile) /root/.config/ghidra/ghidra_11.4_F331B5BBEA-202504251242/jar.resource.copied.files/decompile: /lib64/libstdc++.so.6: version `GLIBCXX_3.4.32' not found (required by /root/.config/ghidra/ghidra_11.4_F331B5BBEA-202504251242/jar.resource.copied.files/decompile)

[root@bd5cde3533df app]# /opt/joern/joern-cli/ghidra2cpg -J-Xmx15360m ./gateway --output /root/test/workspace/gateway/cpg.bin.zip
Exception in thread "main" java.lang.UnsupportedClassVersionError: ghidra/util/exception/InvalidInputException has been compiled by a more recent version of the Java Runtime (class file version 65.0), this version of the Java Runtime only recognizes class file versions up to 61.0
at java.base/java.lang.ClassLoader.defineClass1(Native Method)
at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1017)
at java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:150)
at java.base/jdk.internal.loader.BuiltinClassLoader.defineClass(BuiltinClassLoader.java:862)
at java.base/jdk.internal.loader.BuiltinClassLoader.findClassOnClassPathOrNull(BuiltinClassLoader.java:760)
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClassOrNull(BuiltinClassLoader.java:681)
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:639)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:525)
at io.joern.ghidra2cpg.Main$.<init>(Main.scala:28)
at io.joern.ghidra2cpg.Main$.<clinit>(Main.scala:28)
at io.joern.ghidra2cpg.Main.main(Main.scala)

[README.md] Specify the image tag in README.md

• Specify the image tags to nightly.

Error output:

$ docker pull ghcr.io/joernio/joern
Using default tag: latest
Error response from daemon: manifest unknown

[ylca0]

For fix this problem:
#5875 (comment)