GH Actions: selectively use fail-fast with setup-php (#240)

* GH Actions: selectively use `fail-fast` with setup-php

I've seen some recent build failures due to the `setup-php` action running into a rate limit and not downloading the required version of Composer. In the case of this action, that would make the test runs worthless.

The `setup-php` action runner defaults to _showing_ these type errors in the logs, but not stopping the workflow run.

So, specifically for those jobs where the Composer version is important, I'm adding the `fail-fast` option to `setup-php` to fail the build if the action runner ran into any errors.

Ref: https://github.com/shivammathur/setup-php#fail-fast-optional

* GH Actions: update PHP version for `composer-normalize`

Looks like the `composer-normalize` package has dropped support for PHP < 8.0 as of version `2.29.0`.

Refs:
* https://github.com/ergebnis/composer-normalize/releases/tag/2.29.0
* ergebnis/composer-normalize#998

Co-authored-by: jrfnl <jrfnl@users.noreply.github.com>

.github/workflows/continuous-integration.yml

@@ -20,7 +20,7 @@ jobs:
       - name: "Set up PHP"
         uses: "shivammathur/setup-php@v2"
         with:
-          php-version: 7.4
+          php-version: 8.1
           tools: composer-normalize
           coverage: none
       - name: "Run Composer normalize"
@@ -47,6 +47,8 @@ jobs:
           php-version: "latest"
           tools: "composer:${{ matrix.composer-version }}"
           coverage: "none"
+        env:
+          fail-fast: true
       - name: "Run expect tests"
         run: "composer test"
 
@@ -122,6 +124,8 @@ jobs:
           php-version: "latest"
           tools: "composer:${{ matrix.composer-version }}"
           coverage: "none"
+        env:
+          fail-fast: true
 
       - name: "Test: plain install"
         uses: ./
@@ -251,6 +255,8 @@ jobs:
           php-version: "latest"
           tools: "composer:${{ matrix.composer-version }}"
           coverage: "none"
+        env:
+          fail-fast: true
 
       - name: "Test: plain install"
         uses: ./