Bad suggested array key name in compile time constants

Describe the bug Bad suggested array key name in compile time constants

Describe the eclipse environment Eclipse PDT 8.1.0.202307051059

To Reproduce Steps to reproduce the behavior:

Copy this code
```
<?php
```

const TEST_CONSTANT = [ 'HT_aa_very_long_long_long_key' => 1, 'HT_ab_very_long_long_long_key' => 2, 'HT_ac_very_long_long_long_key' => 3 ];

TEST_CONSTANT['H'];

$_SERVER['HTTP_ACCEPT'];

$runtime_test_array = [ 'HT_runtime_key1_verylong' => 'value1', 'HT_runtime_key2_verylong' => 'value2', 'HT_runtime_key3_verylong' => 'value3', ];

$runtime_test_array['HT'];


3. Move cursor to "['H']" after H on line 9,  press Ctrl + Tab
4. Read suggestions

**Expected behavior**
Constant "TEST_CONSTANT" array keys 'HT_aa_very_long_long_long_key', 'HT_ab_very_long_long_long_key' and 'HT_ac_very_long_long_long_key' must be suggested. Other array keys from $runtime_test_array or $_SERVER must not be suggested.

**Screenshots**

![screen_1](https://github.com/eclipse-pdt/pdt/assets/139230522/8c829bf8-3fce-444b-b5dd-0a290fa0ad1e)
![screen_2](https://github.com/eclipse-pdt/pdt/assets/139230522/1d3d6c39-1286-4042-b6fa-6f9d40d4e697)

eclipse-pdt / pdt

Bad suggested array key name in compile time constants #251