Fix test_all_plugins workflow (#370)

Since ages ago, the `test_all_plugins.yml` workflow was no longer usable
because the GHA matrix allows for a maximum of 256 jobs, and we have far
more plugins than that.

This PR updates the workflow to:

- use npe2api to retrieve the plugin index, instead of the napari hub
API
- randomly select 10 plugins from the list of all plugins (eventually we
may want to update this to select the latest updated plugins or
something)
- use the `$GITHUB_OUTPUT` environment file to set the matrix strategy
output instead of `::set-output` command which is [soon to be
deprecated](https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/)
- use `miniforge3` instead of `mambaforge` for setting up conda because
[a warning in an
action](https://github.com/napari/npe2/actions/runs/12823522845/job/35758149192#step:4:16)
said so

Note the workflow is still triggered in the same ways: via manual
dispatch, or via the `test-all-plugins` label added to a PR

---------

Co-authored-by: Draga Doncila <[email protected]>
Co-authored-by: Peter Sobolewski <[email protected]>
Co-authored-by: Juan Nunez-Iglesias <[email protected]>

Author: 4 people

.github/workflows/test_all_plugins.yml

@@ -1,6 +1,7 @@
 name: Test all plugins
 
 on:
+  # To run this workflow, trigger it manually, or add the label 'test-all-plugins' to a pull request
   pull_request:
     types: [ labeled ]
   workflow_dispatch:
@@ -15,7 +16,13 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - id: plugin_names
-        run: echo "::set-output name=plugins::$(curl -s https://api.napari-hub.org/plugins | jq -c 'keys')"
+        # Query npe2api for index of all plugins, select the keys, turn them into an array, select 10 random
+        # names from that array, convert the "one per line" output back into a string array
+        # save the string array of 10 plugins into the output from this step
+        run: |
+          set -eux
+          DATA=$(echo $(curl -s https://npe2api.vercel.app/api/plugins | jq -c 'keys' | jq -r '.[]' | shuf -n 10 | jq -R -s 'split("\n") | map(select(. != ""))'))
+          echo "plugins=$DATA" >> "$GITHUB_OUTPUT"
     outputs:
       plugins: ${{ steps.plugin_names.outputs.plugins }}
 
@@ -38,8 +45,9 @@ jobs:
 
       - uses: conda-incubator/setup-miniconda@v3
         with:
-          python-version: 3.9
-          miniforge-variant: Mambaforge
+          python-version: '3.10'
+          miniforge-variant: Miniforge3
+          conda-remove-defaults: "true"
           miniforge-version: latest
           use-mamba: true