www-client/chromium: add 121.0.6167.85

This update includes a number of changes:

- Rust is now a mandatory part of the build
- The start of an implementation that enables the use of the bundled
  toolchain. It likely requires aditional work before it is useful.
- Libxml dependency updated to >= 2.12.0
- Dropped legacy gcc fixes

Bug: https://bugs.gentoo.org/922903
Signed-off-by: Matt Jolly <Matt.Jolly@footclan.ninja>

www-client/chromium/Manifest

@@ -1,7 +1,10 @@
 DIST chromium-120.0.6099.129.tar.xz 3283749920 BLAKE2B 889b91eec84fc12d42d0bfe04f41c779b84aab704b47f05a276fa9725696740fc0308764602e87161b1ad73a5bb260cc75e88a8133791dd1b074780363670e51 SHA512 2b12d2af7b469d2896000c785f0252eb260bffb523d8e1b82f1d8ab4098de8e297dd6fe901de58a1f57672c9699523d88342637fc69b5260fe5cf296183e3edf
 DIST chromium-120.0.6099.224.tar.xz 3299542904 BLAKE2B 70c7ab27796f00e18f3c90565ef8b9d8a3daa8c2637f71a207cb95ecdcaf47f95ffed6e51c249595d2af1c3c17bebdba249ba7861b866580c316fad6e1935340 SHA512 64a91dd3683b2b3b982c1a12ba6cb946b32a6dd0d76040036892061fa1d3e889fd61253fd7e05847e3076715e4ab9e7e5f6ff3764bec68c1486c1873d534fb52
+DIST chromium-121.0.6167.85.tar.xz 3332417624 BLAKE2B 8568f224d5a749b01b7521822e3b8b1c0271ea05688f252c5546a8ff1e3cd3b5c12ad3df299258dec8eab11330d4827bc68892fb436706ec436eb7e5abbae502 SHA512 fce8a58524c457d44e2eedf612b8d5e3d2085246e2b554ff2e5354be80722fe0c58271d98af38088868dab11224e4e86784f3fb75197f9e70fe9c15ab8024f9b
 DIST chromium-patches-120.tar.bz2 8630 BLAKE2B aa815521d027036757e5316478c2974e107185662d4c6a200bc7f448558730a3cb11e0a6e28d6a48ff60379813eed10d91c04917002228cf97c8448423cc0994 SHA512 1af05a17c54ea2f23b6f18b40c21304a94076eda4f9dcdf34ff93e1a729ae5a6b69816d32b5855b1cbb412eefaefb3d343fce05afd99347dcf9302a1d47ad3e6
+DIST chromium-patches-121.tar.bz2 5861 BLAKE2B 450591b24933f8bd194865960dcb33dbcf4b560dfe384436ad26d780c6f815b615d419fcaf4b3507cf1ced5c0ab6be9381a5101d1ff1441a3a9425911560c07a SHA512 12f356ae5deafa553b9a709eb72ee7f761fd3f0bd36b9c7542433bbe7825e3dc98ba6639ca8be7fcd766df52c3b77c629c84da545351f5089d7c10343da45f48
 DIST chromium-ppc64le-gentoo-patches-1.tar.xz 5636 BLAKE2B 1d898939df023c59285b27bee552470483ea06375d1ee8d6947b89c5927c23cc7bfec6b49f3b376ece931d11a56f8e2a45791e0f92ad61974fc8c34c1082d89c SHA512 8a71cb007e47cda8e5fe5d185729389e65c48bd322c8ee8b3986bee8571427b959628f2666bda646a3f89ae64197c0957d3626845ff03461dbd5dee4c964d07c
 DIST chromium-profiler-0.2.tar 259952640 BLAKE2B 5e82389fce00b267280d633b26551231c558b80f0c92cd7d60271095a3503365ab673e7a46dc5f74f8a82db1f21262cb24dcc0531d954bab5fb3b175dab3394d SHA512 9fa89a5ab728419683e7495ae676567480987d68a2d589f2aa97bfcbcf123f3c8f97f8bca5f65e5e3f6e41475535add473ded83b9c7a33bb4746a9d05b298a6c
+DIST chromium_119.0.6045.159-1raptor0~deb12u1.debian.tar.xz 522464 BLAKE2B 687636b3c8f9b89db64b16643f6832cd2711f54f4be309d7e8dbaf0b8647bb3400ac095fa497f8a887bde628b521724f21f97a1273ab719f16d9f4114c36a6f0 SHA512 a4724ec5df4f3cfac7ede1514d8e886de20580bb812fed3a3e240e4ad91522b047a7bb065ab9e4402cffb9e8608c5cdc71d10c8b132f27d294ebb44db12294e4
 DIST chromium_120.0.6099.109-1raptor0~deb12u1.debian.tar.xz 534108 BLAKE2B ebfe063c5a141e3cd0f861c753c366297f868a5b475a6d4cfe136baec9b979f909e24f9d6eceeb215b9084a9c087c5fb5eb49e8d26921028b943c119a440356a SHA512 62d4d492f579d1bffeaec9778f275df5ee615f434c1ea5764f7feecec6004bc9862c114caf6b86737a433d97e822f14df5a5871b9cbc7bc891bf48d706d5bccf
 DIST chromium_120.0.6099.199-1raptor0~deb12u1.debian.tar.xz 534452 BLAKE2B 78a59831063256a96730f1b981fa52051ba920055ac863b9114d59532a0db3da664660404a6f2b5d6cd669dece149c7b74d85b995ee826a4d7874462d94b244c SHA512 f345faa72117f66c9819e3d1e304c811ac3a79af77bad1232109f912cbfeadabcdd5e38c29dadedd2e1c7d8447abbb45a426a5c0e9123f55fd853912607c1fd2