HSPC-177: updated gradle version to 8.5 and java to 21 #239

Job	Run time
Build epicbox-clojure image	33s
Build epicbox-haskell image	4m 57s
Build epicbox/debian image	45s
Build epicbox-go image	1m 56s
Build epicbox-hyperskill/go image	2m 51s
Build epicbox-hyperskill/gradle image	1m 46s
Build epicbox-hyperskill/gradle-spring image	1m 18s
Build epicbox-hyperskill/java image	49s
Build epicbox-hyperskill/node image	11m 18s
Build epicbox-hyperskill/node-javascript image	1m 19s
Build epicbox-hyperskill/python image	53s
Build epicbox/hyperstyle image	22s
Build epicbox/java image	42s
Build epicbox/kotlin image	58s
Build epicbox/php image	31s
Build epicbox/node image	33s
Build epicbox/pmd image	38s
Build epicbox/python 3.10 image	5m 47s
Build epicbox/python 3.11 image	5m 48s
Build epicbox/ruby image	1m 58s
Build epicbox/scala2 image	48s
Build epicbox/scala3 image	45s
Build epicbox/typescript image	37s
Build epicbox/mono image	1m 20s
Build epicbox-gcc image	1m 1s
Build epicbox-hyperskill/gcc image	2m 26s
Clean untagged images	1s
	52m 40s

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