[BUG] tests warnings in dex

**Description:**
Tests warnings in dex.

**Steps to reproduce:**
1. Run scripts/tests.sh

**Expected behavior:**
There should be no warnings.

**Actual behavior:**
There are warnings which can be easily fixed.

**Error messages:**
```
#[expected_failure(abort_code = 0x10002)]
│ ^^^^^^^^^^^^^^^^^^^^
│ │
│ Replace value with constant from expected module or add `location=...` attribute.
warning: Test will pass on an abort from *any* module.
┌─ /home/runner/work/move-contract-examples/move-contract-examples/dex/tests/math_amm_tests.move:78:24
│
78 │ #[expected_failure(abort_code = 0x30001)]
│ ^^^^^^^^^^^^^^^^^^^^
│ │
│ Replace value with constant from expected module or add `location=...` attribute.
warning: Test will pass on an abort from *any* module.
┌─ /home/runner/work/move-contract-examples/move-contract-examples/dex/tests/math_amm_tests.move:84:24
│
84 │ #[expected_failure(abort_code = 0x10002)]
│ ^^^^^^^^^^^^^^^^^^^^
│ │
│ Replace value with constant from expected module or add `location=...` attribute.
```

**Environment:**
- OS: Ubuntu 24.04
- Cedra CLI version: 1.0.1

**Possible fix:**
Replace value with constant from expected module or add `location=...` attribute.

Run scripts/tests.sh first, then inspect dex/tests/math_amm_tests.move, especially the expected_failure annotations around lines 78 and 84. Compare the warning guidance with the applicable expected module constants or location attributes. Done means the tests complete without these warnings.

Written by the indexing model from the issue text.