docs: remove trailing colon in header

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Signed-off-by: Jean de Barochez <3436890+jdebarochez@users.noreply.github.com>

Author: jdebarochez

apps/site/pages/en/blog/migrations/axios-to-fetch.mdx

@@ -41,7 +41,7 @@ The codemod supports the following Axios methods and converts them to their Fetc
 - `axios.putForm(url[, data[, config]])`
 - `axios.patchForm(url[, data[, config]])`
 
-## Usage:
+## Usage
 
 The source code for this codemod can be found in the [axios-to-whatwg-fetch directory](https://github.com/nodejs/userland-migrations/tree/main/recipes/axios-to-whatwg-fetch).