Adjust `Tools/wasm` linting and formatting issues found by `ruff`

[dversoza]

Feature or enhancement

After running ruff in CPython, some linting and formatting errors were found.
This issue intends to fix those related to the wasm module under Tools/wasm.

Pitch

In the CPython directory, we run the following command:

ruff .

We can see these three alerts under the Tools/wasm module:

Tools/wasm/wasm_assets.py:9:89: E501 Line too long (115 > 88 characters)
Tools/wasm/wasm_build.py:76:18: F541 [*] f-string without any placeholders
Tools/wasm/wasm_build.py:601:77: F841 [*] Local variable `s` is assigned to but never used

Previous discussion

None.

Linked PRs

• gh-103801: Tools/wasm linting and formatting #103796