Update to node20

node16 is eol, thus updating. See also https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/

Many popular actions (like checkout) already updated and everything should
work fine.

The entire package-lock.json was regenerated via node20.

Also explicitly setting the node version in the lint action.

CONTRIBUTING.md

@@ -11,11 +11,11 @@ convention, are also checked in.
 
 - Create Conda env with `nodejs`:
 
-We use NodeJS version 16 for now.
+We use NodeJS version 20 for now.
 
 ```bash
-conda create -n github-action nodejs=16 -c conda-forge
-conda activate
+conda create -n github-action nodejs=20 -c conda-forge
+conda activate github-action
 ```
 
 - Install NodeJS dependencies:

action.yml

@@ -3,7 +3,7 @@ author: Gonzalo Peña-Castellanos (@goanpeca)
 description: "Set up Conda package and environment manager with Miniconda."
 
 runs:
-  using: "node16"
+  using: "node20"
   main: "dist/setup/index.js"
   post: "dist/delete/index.js"
   post-if: "success() && env.INPUT_RUN_POST == 'true'"