PY-32918 Handle enter in f-string right before the closing quote

in the context where we don't need to insert additional backslashes.

python/src/com/jetbrains/python/editor/PythonEnterHandler.java

@@ -135,7 +135,8 @@ public class PythonEnterHandler extends EnterHandlerDelegateAdapter {
     if (stringElement != null && (!stringElement.isFormatted() ||
                                   nodeType == PyTokenTypes.FSTRING_TEXT ||
                                   // Caret should be right before the opening brace of an f-string fragment 
-                                  nodeType == PyTokenTypes.FSTRING_FRAGMENT_START)) {
+                                  nodeType == PyTokenTypes.FSTRING_FRAGMENT_START || 
+                                  nodeType == PyTokenTypes.FSTRING_END)) {
       if (stringElement.isTripleQuoted() || nodeType == PyTokenTypes.DOCSTRING) {
         return Result.Continue;
       }

python/testSrc/com/jetbrains/python/PyEditingTest.java

@@ -126,6 +126,12 @@ public class PyEditingTest extends PyTestCase {
                                         "    f'{42}bar'");
   }
 
+  // PY-32918
+  public void testEnterInFStringRightBeforeClosingQuote() {
+    doTestEnter("(f'foo{42}bar<caret>')", "(f'foo{42}bar'\n" +
+                                          " f'')");
+  }
+
   public void testOvertypeFromInside() {
     assertEquals("''", doTestTyping("''", 1, '\''));
   }