Remove release CI workflow and add coverage badge

Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>

Author: echobt

.github/workflows/release.yml

@@ -4,7 +4,8 @@
 
 **Terminal Benchmark Challenge — WASM Evaluation Module for Platform-v2**
 
-[![License](https://img.shields.io/github/license/PlatformNetwork/term-challenge)](https://github.com/PlatformNetwork/term-challenge/blob/main/LICENSE)
+[![Coverage](https://img.shields.io/codecov/c/github/PlatformNetwork/term-challenge-v2)](https://codecov.io/gh/PlatformNetwork/term-challenge-v2)
+[![License](https://img.shields.io/github/license/PlatformNetwork/term-challenge-v2)](https://github.com/PlatformNetwork/term-challenge-v2/blob/main/LICENSE)
 [![Rust](https://img.shields.io/badge/rust-1.90+-orange.svg)](https://www.rust-lang.org/)
 
 ![Term Challenge Banner](assets/banner.jpg)