test: GoTimeUtilTest asserts optional with assertj

Update GoTimeUtilTest.java

 GoTimeUtilTest is refactored to not directly call Optional.get().
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Merge pull request #1 from kushagrasinha123ks/kushagra/issue#2970

Update GoTimeUtilTest.java
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Revert "Update GoTimeUtilTest.java"
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Merge pull request #2 from kushagrasinha123ks/revert-1-kushagra/issue#2970

Revert "Update GoTimeUtilTest.java"
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Update GoTimeUtilTest.java

GoTimeUtilTest is refactored to not directly call Optional.get().
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Update GoTimeUtilTest.java

inlined the method calls in conversion function
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Update GoTimeUtilTest.java

removed the unused imports.

jkube-kit/enricher/api/src/test/java/org/eclipse/jkube/kit/enricher/api/util/GoTimeUtilTest.java

@@ -32,8 +32,7 @@ class GoTimeUtilTest {
     @ParameterizedTest(name = "duration ''{0}'' should be ''{1}'' seconds")
     @MethodSource("data")
     void conversion(String duration, int expectedDuration) {
-        int result = GoTimeUtil.durationSeconds(duration).get();
-        assertThat(result).isEqualTo(expectedDuration);
+        assertThat(GoTimeUtil.durationSeconds(duration)).isPresent().contains(expectedDuration);
     }
 
     static Stream<Arguments> data() {