Add build dependencies: Java 8, IcedTea-Web, iDRAC libs

- java8.tar.gz (Temurin JRE 8)
- jdk8.tar.gz (Temurin JDK 8, unused but kept for reference)
- icedtea-web.zip (1.8.8)
- idrac-libs/: avctKVM.jar + native .so files

.gitignore

@@ -1,5 +1,2 @@
-*.tar.gz
-*.zip
 build-dir/
-.flatpak-builder/
-idrac-libs/
+.flatpak-builder/