MINIFICPP-2713 curl: upgrade to 8.18.0

[szaszm]

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[szaszm]

I'm getting zstd and brotli related linker errors locally, but at first I wasn't sure if it's related to the upgrade. After checking the changelog, it seems it probably is, since curl changed some defaults around those compression algorithms. I think their build scripts find the libs on my system, which causes curl to enable them, but they're not available in our build environment. I'll try to link curl to zstd, since we're building that anyway for other extensions, but disable brotli. In the old version, both used to be disabled by default.

[szaszm]

I gave up on making zstd work and disabled it instead. The linux build works now, but windows has a different curl-related issue:

2026-02-09T13:08:12.5810183Z libcurl.lib(url.c.obj) : error LNK2019: unresolved external symbol __imp_if_nametoindex referenced in function zonefrom_url

I didn't debug this one yet.