[ci skip] Use commit timestamp instead of build time in manifest (#6161)

patches/server/0001-Setup-Gradle-project.patch

@@ -20,10 +20,10 @@ index 67fb370cad6924895a6b27052dbd5c1767e3f0c9..3e05459f27c4c5697ae65da504d67a6a
  /.project
 diff --git a/build.gradle.kts b/build.gradle.kts
 new file mode 100644
-index 0000000000000000000000000000000000000000..e76b9f9012c7ba7253f455fa92b3891737f4ffd3
+index 0000000000000000000000000000000000000000..f99a9702fe9282a1982c25cd0c003d8df80e97de
 --- /dev/null
 +++ b/build.gradle.kts
-@@ -0,0 +1,145 @@
+@@ -0,0 +1,146 @@
 +import com.github.jengelman.gradle.plugins.shadow.transformers.Log4j2PluginsCacheFileTransformer
 +import com.github.jengelman.gradle.plugins.shadow.transformers.Transformer
 +import io.papermc.paperweight.util.Git
@@ -72,11 +72,12 @@ index 0000000000000000000000000000000000000000..e76b9f9012c7ba7253f455fa92b38917
 +        val git = Git(rootProject.layout.projectDirectory.path)
 +        val gitHash = git("rev-parse", "--short=7", "HEAD").getText().trim()
 +        val implementationVersion = System.getenv("BUILD_NUMBER") ?: "\"$gitHash\""
++        val date = git("show", "-s", "--format=%ci", gitHash).getText().trim() // Paper
 +        attributes(
 +            "Main-Class" to "org.bukkit.craftbukkit.Main",
 +            "Implementation-Title" to "CraftBukkit",
 +            "Implementation-Version" to "git-Paper-$implementationVersion",
-+            "Implementation-Vendor" to SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'").format(Date()), // Paper
++            "Implementation-Vendor" to date, // Paper
 +            "Specification-Title" to "Bukkit",
 +            "Specification-Version" to project.version,
 +            "Specification-Vendor" to "Bukkit Team",