Add support RFC 5746 secure renegotiation for site about getcomposer.org

[Seldaek]

I am not sure what this is about nor how to fix it tbh, as https://www.ssllabs.com/ssltest/analyze.html?d=getcomposer.org&s=142.44.245.229 shows it is supported:

That said, we should try dropping TLSv1.1 support at last, and I can try to modernize our ssl config a little, see if it helps resolve this too.

[Seldaek]

Ok I dropped TLSv1.1 now and enabled client selection of ciphers again, I am hoping this helps the problem for you but I cannot test it so would appreciate if you can confirm. If so and nobody complains I'll try to deploy this to packagist.org & the JSON repo there as well (but that's used by more people/machines).

[darkdarin]

I tested in more depth, and realized that this is probably not a problem with getcomposer.org and packagist.org.
This issue only reproduces from my work environment and is likely related to the use of a corporate firewall.
On a clean debian bookworm + openssl 3.0.9 from any networks, all resources are accessed correctly.

I apologize for the incorrect issue and your wasted time.

[Seldaek]

No worries, it nudged me to finally get rid of TLS1.1 which is good, so far nobody complained :)