J2CL: expose ImmutableMap.ofEntries to JS

Callers from JS can use `java.util.Map.entry(key, value)` to create `Entry`
instances to pass to this. For example:

```js
const m = new Map([["key1", "value1"], ["key2", "value2"]]);
const immutableMap = ImmutableMap.ofEntries(
    ...m.entries().map(([k, v]) => java.util.Map.entry(k, v))
);
```

RELNOTES=n/a
PiperOrigin-RevId: 883670695

Author: kevinoconnor7

guava-gwt/src-super/com/google/common/collect/super/com/google/common/collect/ImmutableMap.java

@@ -36,6 +36,7 @@
 import java.util.function.Function;
 import java.util.stream.Collector;
 import java.util.stream.Collectors;
+import jsinterop.annotations.JsMethod;
 import org.jspecify.annotations.Nullable;
 
 /**
@@ -242,6 +243,12 @@ public static <K, V> ImmutableMap<K, V> ofEntries(Entry<? extends K, ? extends V
     return new RegularImmutableMap<>(entries);
   }
 
+  /** ImmutableMap.ofEntries API that is friendly to use from JavaScript. */
+  @JsMethod(name = "ofEntries")
+  static <K, V> ImmutableMap<K, V> jsOfEntries(Entry<? extends K, ? extends V>... entries) {
+    return new RegularImmutableMap<>(entries);
+  }
+
   public static <K, V> Builder<K, V> builder() {
     return new Builder<K, V>();
   }