Don't install gulp-cli globally in the GitHub Actions workflows

It's recommended to always install dependencies locally in the project
folder because global dependencies can easily conflict with other
projects and, because they are not managed by the project, diverge from
versions defined in e.g. `package.json`. Previously we installed
`gulp-cli` globally because at the time we lacked a convenient mechanism
to use Gulp otherwise, but nowadays NPM provides the `npx` command for
that purpose and recommends using it over global installations (see
https://docs.npmjs.com/downloading-and-installing-packages-globally
and PR mozilla#17489 that provided the ground work for using it).

This commit therefore updates our GitHub Actions workflows to no longer
install `gulp-cli` globally but instead install it locally from the
already existing entries in `package.json` like all other dependencies
we use. Not only does this remove the special-casing for `gulp-cli`
which simplifies the workflow definitions, it also ensures that the
version ranges provided in `package.json` are respected. This makes the
local and workflow setups more similar, but is also relevant for the
upcoming upgrade to Gulp 5 which from a quick try is a bit involved and
having `package.json` be the single source of truth for the dependency
versions we use is therefore important.

.github/workflows/ci.yml

@@ -24,14 +24,11 @@ jobs:
         with:
           node-version: ${{ matrix.node-version }}
 
-      - name: Install Gulp
-        run: npm install -g gulp-cli
-
-      - name: Install other dependencies
+      - name: Install dependencies
         run: npm install
 
       - name: Run external tests
-        run: gulp externaltest
+        run: npx gulp externaltest
 
       - name: Run CLI unit tests
-        run: gulp unittestcli
+        run: npx gulp unittestcli

.github/workflows/font_tests.yml

@@ -45,10 +45,7 @@ jobs:
         with:
           node-version: ${{ matrix.node-version }}
 
-      - name: Install Gulp
-        run: npm install -g gulp-cli
-
-      - name: Install other dependencies
+      - name: Install dependencies
         run: npm install
 
       - name: Use Python 3.12
@@ -61,4 +58,4 @@ jobs:
         run: pip install fonttools
 
       - name: Run font tests
-        run: gulp fonttest --headless
+        run: npx gulp fonttest --headless

.github/workflows/lint.yml

@@ -24,14 +24,11 @@ jobs:
         with:
           node-version: ${{ matrix.node-version }}
 
-      - name: Install Gulp
-        run: npm install -g gulp-cli
-
-      - name: Install other dependencies
+      - name: Install dependencies
         run: npm install
 
       - name: Run lint
-        run: gulp lint
+        run: npx gulp lint
 
       - name: Run lint-chromium
-        run: gulp lint-chromium
+        run: npx gulp lint-chromium

.github/workflows/publish_website.yml

@@ -26,14 +26,11 @@ jobs:
         with:
           node-version: ${{ matrix.node-version }}
 
-      - name: Install Gulp
-        run: npm install -g gulp-cli
-
-      - name: Install other dependencies
+      - name: Install dependencies
         run: npm install
 
       - name: Build the website
-        run: gulp web
+        run: npx gulp web
 
       - name: Archive the website
         shell: sh

.github/workflows/types_tests.yml

@@ -24,11 +24,8 @@ jobs:
         with:
           node-version: ${{ matrix.node-version }}
 
-      - name: Install Gulp
-        run: npm install -g gulp-cli
-
-      - name: Install other dependencies
+      - name: Install dependencies
         run: npm install
 
       - name: Run types tests
-        run: gulp typestest
+        run: npx gulp typestest