main/zsh: don't attempt to add ~/bin to PATH by default

Does not work correctly as /etc/profile (sourced by zprofile)
overwrites PATH again. Besides, I believe that locations such as ~/bin
should be explicitly enabled by the user. Other shells (e.g. bash, mksh,
…) do not add ~/bin to PATH by default either.

Fixes #11371
7 jobs for !6563 with zsh-home-bin in 1 minute (queued for 1 second)
latest detached
Status Job ID Name Coverage
  Lint
passed #88826
x86_64 docker-alpine
lint

00:00:19

 
  Build
passed #88831
aarch64 ci-build docker-alpine
build-aarch64

00:00:24

passed #88832
armv7 ci-build docker-alpine
build-armv7

00:00:28

passed #88830
ppc64le ci-build docker-alpine
build-ppc64le

00:00:40

passed #88829
s390x ci-build docker-alpine
build-s390x

00:00:21

passed #88828
x86 ci-build docker-alpine
build-x86

00:00:21

passed #88827
x86_64 ci-build docker-alpine
build-x86_64

00:00:21