Drop support of Node 16

[rschnekenbu]

According to https://nodejs.org/en/about/releases/,

• Node 16 is not maintained anymore.
• The next active release for Node (22) is planned for October this year

We should then drop the support from Node 16 in our builds (https://github.com/eclipse-theia/theia/blob/master/doc/runtime-policy.md).

Node 16 support blocked the update for jsdom for example (see https://github.com/eclipse-theia/theia/issues/13943).