njs: upgrade to 0.9.2

[macbre]

This release adds HTTP keepalive support to ngx.fetch() API. Additionally, the njs.on('exit') API was added for qjs engine.

What's Changed

Change: increasing the default stack size to 160k. by @xeioex in https://github.com/nginx/njs/pull/950
Fixed building QuickJS support with clang 19. by @xeioex in https://github.com/nginx/njs/pull/958
Fix long running streams in tcp stream by @xeioex in https://github.com/nginx/njs/pull/954
Qjs exit hook by @xeioex in https://github.com/nginx/njs/pull/959
Fetch keepalive support. by @xeioex in https://github.com/nginx/njs/pull/963
Fixed build with GCC 15 and O3 optimization level. by @xeioex in https://github.com/nginx/njs/pull/965
Fix no ssl build by @xeioex in https://github.com/nginx/njs/pull/966