fixed PY-8948 Not closed quote in subscription breaks parsing for the whole file

python/testData/psi/NotClosedSlice.py

@@ -0,0 +1,3 @@
+a["key""]"
+if True:
+    pass

python/testData/psi/NotClosedSlice.txt

@@ -0,0 +1,25 @@
+PyFile:NotClosedSlice.py
+  PyExpressionStatement
+    PyConditionalExpression
+      PySubscriptionExpression
+        PyReferenceExpression: a
+          PsiElement(Py:IDENTIFIER)('a')
+        PsiElement(Py:LBRACKET)('[')
+        PyConditionalExpression
+          PyStringLiteralExpression: key]
+            PsiElement(Py:SINGLE_QUOTED_STRING)('"key"')
+            PsiElement(Py:SINGLE_QUOTED_STRING)('"]"')
+        PsiErrorElement:']' expected
+          <empty list>
+  PsiWhiteSpace('\n')
+  PyIfStatement
+    PyIfPartIf
+      PsiElement(Py:IF_KEYWORD)('if')
+      PsiWhiteSpace(' ')
+      PyReferenceExpression: True
+        PsiElement(Py:IDENTIFIER)('True')
+      PsiElement(Py:COLON)(':')
+      PsiWhiteSpace('\n    ')
+      PyStatementList
+        PyPassStatement
+          PsiElement(Py:PASS_KEYWORD)('pass')