ci: Cleanup quotes

Prefer single quotes over double quotes, and omit them where possible.

.github/workflows/release_nightly.yml

@@ -3,7 +3,7 @@ name: Release Nightly
 on:
   # Run nightly
   schedule:
-    - cron: "0 0 * * *"
+    - cron: '0 0 * * *'
 
   # Allow for manual dispatch on GitHub
   workflow_dispatch:
@@ -235,7 +235,7 @@ jobs:
       - name: Setup Node.js
         uses: actions/setup-node@v1
         with:
-          node-version: "14"
+          node-version: '14'
 
       # wasm-bindgen-cli version must match wasm-bindgen crate version.
       # Be sure to update in test_web.yml, web/Cargo.toml and web/README.md.

.github/workflows/test_rust.yml

@@ -32,10 +32,10 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        rust_version: ["stable", "beta"]
+        rust_version: [stable, beta]
         os: [ubuntu-latest, windows-latest, macOS-latest]
         include:
-          - rust_version: "nightly"
+          - rust_version: nightly
             os: ubuntu-latest
 
     steps:
@@ -73,7 +73,7 @@ jobs:
         if: matrix.os == 'ubuntu-latest' || matrix.os == 'windows-latest'
         uses: actions-rs/cargo@v1
         env:
-          XDG_RUNTIME_DIR: "" # dummy value, just to silence warnings about it missing
+          XDG_RUNTIME_DIR: '' # dummy value, just to silence warnings about it missing
         with:
           command: test
           args: --features imgtests

.github/workflows/test_web.yml

@@ -31,7 +31,7 @@ jobs:
       matrix:
         node_version: ['12', '14']
         # We most likely don't care about Rust versions here, we'll catch those issues in test_rust.yml.
-        rust_version: ['stable']
+        rust_version: [stable]
         # MIKE: Turning off macOS-latest for now (flaky tests on CI).
         os: [ubuntu-latest, windows-latest]