deps: bump LLVM-> 15.0.1

[RiverPhillips]

bump LLVM-> 15.0.1 to unblock #23227 in envoy

[keith]

you need to update the shas below this line as well

[RiverPhillips]

Looks like an x86_64 llvm hasn't yet been published. I'll have a go at doing that then come back to this

[phlax]

@RiverPhillips 15.0.2 seems to have some linux/x86 bins - not for ubuntu - but might work

@lizan im wondering if we can use the clang/llvm from apt.llvm.org now - iirc there was an issue re missing PIE, wondering if this is still the case - i think i read somewhere a while back that this is now the default but not sure

[moderation]

15.0.3 is the latest release - https://github.com/llvm/llvm-project/releases/tag/llvmorg-15.0.3

[phlax]

releases of llvm seem pretty sporadic - every version has assets for a different set of arches/platforms

i does seem like there is available bins for 15.0.5 tho - ill have a go at updating

[moderation]

Superseded by https://github.com/envoyproxy/envoy-build-tools/pull/342