chore: update user-agent (#1685)

## Checklist

- [x] I have read the [contribution
guidelines](https://github.com/ooni/probe-cli/blob/master/CONTRIBUTING.md)
- [x] reference issue for this pull request:
ooni/probe#2841
- [ ] if you changed anything related to how experiments work and you
need to reflect these changes in the ooni/spec repository, please link
to the related ooni/spec pull request: <!-- add URL here -->
- [ ] if you changed code inside an experiment, make sure you bump its
version number

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## Description

This diff updates the user-agent to the most widely used agent as of
2025-02-09

internal/model/http.go

@@ -13,9 +13,9 @@ const (
 	HTTPHeaderAcceptLanguage = "en-US,en;q=0.9"
 
 	// HTTPHeaderUserAgent is the User-Agent header used for measuring. The current header
-	// is 31.36% of the browser population as of 2024-11-25 according to the
+	// is 40.98% of the browser population as of 2025-02-09 according to the
 	// https://www.useragents.me/ webpage.
-	HTTPHeaderUserAgent = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.6 Safari/605.1.1"
+	HTTPHeaderUserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/132.0.0.0 Safari/537.3"
 )
 
 // Additional strings used to report HTTP errors. They're currently only used by