ci: fix node version when publishing

[vince-fugnitto]

What it does

Following #11210, we need to update the node version we use when publishing, else we will get an error as the check does not pass:

Run yarn --skip-integrity-check --network-timeout 100000
yarn install v1.22.18
$ node-gyp install
gyp info it worked if it ends with ok
gyp info using node-gyp@5.1.0
gyp info using node@[12](https://github.com/eclipse-theia/theia/runs/6777317063?check_suite_focus=true#step:5:13).22.12 | linux | x64
gyp http GET https://nodejs.org/download/release/v12.22.12/node-v12.22.12-headers.tar.gz
gyp http 200 https://nodejs.org/download/release/v12.22.12/node-v12.22.12-headers.tar.gz
gyp http GET https://nodejs.org/download/release/v12.22.12/SHASUMS256.txt
gyp http 200 https://nodejs.org/download/release/v12.22.12/SHASUMS256.txt
12.22.12
gyp info ok 
[1/5] Validating package.json...
error @theia/monorepo@0.0.0: The engine "node" is incompatible with this module. Expected version ">=[14](https://github.com/eclipse-theia/theia/runs/6777317063?check_suite_focus=true#step:5:15)". Got "12.[22](https://github.com/eclipse-theia/theia/runs/6777317063?check_suite_focus=true#step:5:23).12"
error Found incompatible module.
info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.
Error: Process completed with exit code 1.

How to test

N/A.

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

Signed-off-by: vince-fugnitto vincent.fugnitto@ericsson.com

[msujew]

LGTM 👍

[paul-marechal]

At least we're sure that the engine check works now :p