Remove !/vendor from .dockerignore

[nick-lai]

Q	A
Is bugfix?	❌
New feature?	❌
Breaks BC?	❌
Fixed issues	-

Dockerfile:

app/docker/Dockerfile

Lines 38 to 45 in 77b409a

	RUN --mount=type=cache,target=/tmp/cache \
	<<SH
	set -eo pipefail
	set -x
	composer install --no-dev --no-progress --no-interaction --classmap-authoritative && \
	rm composer.lock composer.json
	SH

[samdark]

Thank you!