tools: check-imports using utf-8

[cclauss]

This PR uses io.open(encoding="utf-8") to resolve a UnicodeDecodeError on Python 3 after the fix in #30218 has been applied.

This can be replicated by running docker build . using the following:

Dockerfile

FROM ubuntu:bionic # Install tools RUN apt-get update RUN apt-get install -y build-essential python3 python3-pip ninja-build make g++ vim git sudo # Expose ports used by net tests ENV NODE_COMMON_PORT=12346 EXPOSE 12346 # debug port used by v8 debugger EXPOSE 5858 # debug port used by v8 insepctor EXPOSE 9229 # Set up user node-dev: the tests fail when run by the root RUN adduser --disabled-password --gecos '' node-dev RUN adduser node-dev sudo RUN echo '%sudo ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers USER node-dev WORKDIR /home/node-dev ENV HOME /home/node-dev # Clone the code and build RUN git clone --depth=1 https://github.com/nodejs/node.git WORKDIR /home/node-dev/node RUN python3 -m pip install setuptools RUN python3 ./configure --ninja ENV BUILD_WITH ninja RUN make -j2 test 

Checklist

• commit message follows commit guidelines

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/26292/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/26299/

[joyeecheung]

Thanks!

(And makes me wonder whether it is useful to add an dockerfile to BUILDING.md since it's pretty easy to understand what's necessary to have a working dev environment from a glance)

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/26334/

[cclauss]

Landed in aa4e54e

@targos is this in time for inclusion in #30262 ?