Outstanding upstream PRs

[Ramblurr]

h2o-zig depends on a few changes I've submitted upstream. This issue will track their process of being accepted.

boringssl zig:

• update boringssl to 0.20251124.0 LukasKastern/boringssl#7
• PR changes for PIC code to fix aarch64-linux

brotli zig:

• Update to support zig 0.15.2 0x546F6D/brotli.zig#2
• Add build option for PIC 0x546F6D/brotli.zig#3

zlib zig:

• Add build option for PIC allyourcodebase/zlib#11

openssl zig

• Update to openssl 3.6.0 dzfrias/openssl-zig#2

picotls

• fix aegis call sites after breaking changes in 0.9.0 h2o/picotls#584

h2o

• Add quic/http3 to libh2o simple.c example h2o/h2o#3547
• Implement on-the-fly zstd compression h2o/h2o#3529
• guard DHE cipher constants for BoringSSL compatibility h2o/h2o#3548