fix: release build scripts (#1286)

* update all builders

* rbuilder images are prefixed by osmolabs

* update makefile

* use root instead of builder user and other minor changes

* correct lib path in Makefile

* LINK_STATICALLY in Makefile

* docs for builder

* update README

* changelog entry

* remove make clean from .build.sh

* improve readme

* remove spurious whitespace in Makefile

* fix formatting for build-reproducible

* update cosmwasm path in makefile

* copy from /home/builder in build-reproducible

* change wasm file pemissions to non-root