Add back inputs on processResources

I kinda thought that Gradle would be smart enough to know that these
were input (given they're passed to expand), but apparently not :/.

projects/core/build.gradle.kts

@@ -40,6 +40,8 @@ dependencies {
 }
 
 tasks.processResources {
+    inputs.property("gitHash", cct.gitHash)
+
     var props = mapOf("gitContributors" to cct.gitContributors.get().joinToString("\n"))
     filesMatching("data/computercraft/lua/rom/help/credits.md") { expand(props) }
 }