Remove references to java 17

Author: md5sha256

.github/workflows/gradle.yml

@@ -12,12 +12,6 @@ jobs:
     runs-on: "${{ matrix.os }}"
     steps:
       - uses: actions/checkout@v4
-      - name: Set up JDK 17
-        uses: actions/setup-java@v4
-        with:
-          java-version: '17'
-          distribution: 'zulu'
-          cache: 'gradle'
       - name: Set up JDK 21
         uses: actions/setup-java@v4
         with:

gradle/build-logic/src/main/kotlin/hyperverse.base-conventions.gradle.kts

@@ -5,9 +5,9 @@ plugins {
 
 indra {
     javaVersions {
-        minimumToolchain(17)
-        target(17)
-        testWith().set(setOf(17))
+        minimumToolchain(21)
+        target(21)
+        testWith().set(setOf(21))
     }
     checkstyle().set(libs.versions.checkstyle)
 }