drop matrix from the lint job

[turadg]

What is the Problem Being Solved?

The lint job does static analysis, but it's configured to run against multiple Node runtimes. Only one is needed and it shouldn't have a matrix because that necessitates updating its Required check when bumping Node versions.

Description of the Design

1. Take the matrix out of

   endo/.github/workflows/ci.yml

   Lines 18 to 28 in b02f0e2

   	name: lint
   	# begin macro
   	runs-on: ${{ matrix.platform }}
   	strategy:
   	fail-fast: false
   	matrix:
   	node-version: [18.x, 20.x]
   	platform: [ubuntu-latest]

2. A repo admin updates settings to require the plain "lint" job, not the runtime-scoped one

Security Considerations

Scaling Considerations

Test Plan

Compatibility Considerations

Upgrade Considerations