fix(core): prevent the error when the condition is split into groups of 10 and 1 in Fn.conditionOr() (#25708)

Closes #25696

>The problem I'm running into is for a list of 11 elements. CDK generates two Fn::Or expressions: One with 10 elements and one with 1 element. When deployment this stack, CloudFormation complains that an Fn::Or must contain at least 2 elements.

reproduce code: #25696 (comment)
approach: #25696 (comment)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: wafuwafu13

packages/aws-cdk-lib/core/lib/cfn-fn.ts

@@ -334,7 +334,10 @@ export class Fn {
     if (conditions.length === 1) {
       return conditions[0] as ICfnRuleConditionExpression;
     }
-    return Fn.conditionOr(..._inGroupsOf(conditions, 10).map(group => new FnOr(...group)));
+    if (conditions.length <= 10) {
+      return new FnOr(...conditions);
+    }
+    return Fn.conditionOr(..._inGroupsOf(conditions, 10).map(group => Fn.conditionOr(...group)));
   }
 
   /**

packages/aws-cdk-lib/core/test/condition.test.ts

@@ -59,4 +59,104 @@ describe('condition', () => {
       },
     });
   });
+
+  test('condition length is 10n + 1 in Fn.conditionOr', () => {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const expression = cdk.Fn.conditionOr(
+      cdk.Fn.conditionEquals('a', '1'),
+      cdk.Fn.conditionEquals('b', '2'),
+      cdk.Fn.conditionEquals('c', '3'),
+      cdk.Fn.conditionEquals('d', '4'),
+      cdk.Fn.conditionEquals('e', '5'),
+      cdk.Fn.conditionEquals('f', '6'),
+      cdk.Fn.conditionEquals('g', '7'),
+      cdk.Fn.conditionEquals('h', '8'),
+      cdk.Fn.conditionEquals('i', '9'),
+      cdk.Fn.conditionEquals('j', '10'),
+      cdk.Fn.conditionEquals('k', '11'),
+    );
+
+    // WHEN
+    new cdk.CfnCondition(stack, 'Condition', { expression });
+
+    // THEN
+    expect(toCloudFormation(stack)).toEqual({
+      Conditions: {
+        Condition: {
+          'Fn::Or': [
+            {
+              'Fn::Or': [
+                { 'Fn::Equals': ['a', '1'] },
+                { 'Fn::Equals': ['b', '2'] },
+                { 'Fn::Equals': ['c', '3'] },
+                { 'Fn::Equals': ['d', '4'] },
+                { 'Fn::Equals': ['e', '5'] },
+                { 'Fn::Equals': ['f', '6'] },
+                { 'Fn::Equals': ['g', '7'] },
+                { 'Fn::Equals': ['h', '8'] },
+                { 'Fn::Equals': ['i', '9'] },
+                { 'Fn::Equals': ['j', '10'] },
+              ],
+            },
+            {
+              'Fn::Equals': ['k', '11'],
+            },
+          ],
+        },
+      },
+    });
+  });
+
+  test('condition length is more than 10 in Fn.conditionOr', () => {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const expression = cdk.Fn.conditionOr(
+      cdk.Fn.conditionEquals('a', '1'),
+      cdk.Fn.conditionEquals('b', '2'),
+      cdk.Fn.conditionEquals('c', '3'),
+      cdk.Fn.conditionEquals('d', '4'),
+      cdk.Fn.conditionEquals('e', '5'),
+      cdk.Fn.conditionEquals('f', '6'),
+      cdk.Fn.conditionEquals('g', '7'),
+      cdk.Fn.conditionEquals('h', '8'),
+      cdk.Fn.conditionEquals('i', '9'),
+      cdk.Fn.conditionEquals('j', '10'),
+      cdk.Fn.conditionEquals('k', '11'),
+      cdk.Fn.conditionEquals('l', '12'),
+    );
+
+    // WHEN
+    new cdk.CfnCondition(stack, 'Condition', { expression });
+
+    // THEN
+    expect(toCloudFormation(stack)).toEqual({
+      Conditions: {
+        Condition: {
+          'Fn::Or': [
+            {
+              'Fn::Or': [
+                { 'Fn::Equals': ['a', '1'] },
+                { 'Fn::Equals': ['b', '2'] },
+                { 'Fn::Equals': ['c', '3'] },
+                { 'Fn::Equals': ['d', '4'] },
+                { 'Fn::Equals': ['e', '5'] },
+                { 'Fn::Equals': ['f', '6'] },
+                { 'Fn::Equals': ['g', '7'] },
+                { 'Fn::Equals': ['h', '8'] },
+                { 'Fn::Equals': ['i', '9'] },
+                { 'Fn::Equals': ['j', '10'] },
+              ],
+            },
+            {
+              'Fn::Or': [
+                { 'Fn::Equals': ['k', '11'] },
+                { 'Fn::Equals': ['l', '12'] },
+              ],
+            },
+          ],
+        },
+      },
+    });
+  });
 });