Reconfigure rollup to prevent build warnings
Sets: https://github.com/rollup/plugins/tree/master/packages/replace#preventassignment to true, to prevent build warning:
(!) Plugin replace: @rollup/plugin-replace: 'preventAssignment' currently defaults to false. It is recommended to set this option to `true`, as the next major version will default this option to `true`.
Why this happened
This was caused by updating @rollup/plugin-replace
to 2.4.0+ in !1548 (merged).
On the default branch, we saw it at https://gitlab.com/gitlab-org/gitlab-docs/-/jobs/1047900803 for the first time due to merging !1548 (merged) while we did not see it at the previous commit on the default branch: https://gitlab.com/gitlab-org/gitlab-docs/-/jobs/1045658862
cf. https://github.com/rollup/plugins/pull/798
CC @tnir
Edited by Takuya Noguchi