Bump shivammathur/setup-php from 2.3.0 to 2.3.1

Bumps [shivammathur/setup-php](https://github.com/shivammathur/setup-php) from 2.3.0 to 2.3.1.
- [Release notes](https://github.com/shivammathur/setup-php/releases)
- [Commits](shivammathur/setup-php@2.3.0...7bdd1ac)

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/continuous-integration.yml

@@ -26,7 +26,7 @@ jobs:
         uses: actions/checkout@v2.3.1
 
       - name: "Install PHP with extensions"
-        uses: shivammathur/setup-php@2.3.0
+        uses: shivammathur/setup-php@2.3.1
         with:
           coverage: none
           extensions: "mbstring, json"
@@ -78,7 +78,7 @@ jobs:
         uses: actions/checkout@v2.3.1
 
       - name: "Install PHP with extensions"
-        uses: shivammathur/setup-php@2.3.0
+        uses: shivammathur/setup-php@2.3.1
         with:
           coverage: none
           extensions: "mbstring, json"
@@ -122,7 +122,7 @@ jobs:
         uses: actions/checkout@v2.3.1
 
       - name: "Install PHP with extensions"
-        uses: shivammathur/setup-php@2.3.0
+        uses: shivammathur/setup-php@2.3.1
         with:
           coverage: none
           extensions: "mbstring, json"
@@ -165,7 +165,7 @@ jobs:
         uses: actions/checkout@v2.3.1
 
       - name: "Install PHP with extensions"
-        uses: shivammathur/setup-php@2.3.0
+        uses: shivammathur/setup-php@2.3.1
         with:
           coverage: pcov
           extensions: "mbstring, json"
@@ -205,7 +205,7 @@ jobs:
         uses: actions/checkout@v2.3.1
 
       - name: "Install PHP with extensions"
-        uses: shivammathur/setup-php@2.3.0
+        uses: shivammathur/setup-php@2.3.1
         with:
           coverage: pcov
           extensions: "mbstring"