Run CI on workflow_dispatch

Author: oalders

.github/workflows/linux.yml

@@ -1,3 +1,4 @@
+---
 name: linux
 on:
   push:
@@ -6,6 +7,7 @@ on:
     tags-ignore:
       - '*'
   pull_request:
+  workflow_dispatch:
 jobs:
   perl:
     runs-on: ubuntu-latest

.github/workflows/macos.yml

@@ -1,3 +1,4 @@
+---
 name: macos
 on:
   push:
@@ -6,6 +7,7 @@ on:
     tags-ignore:
       - '*'
   pull_request:
+  workflow_dispatch:
 jobs:
   perl:
     runs-on: macos-latest

.github/workflows/windows.yml

@@ -1,3 +1,4 @@
+---
 name: windows
 on:
   push:
@@ -6,6 +7,7 @@ on:
     tags-ignore:
       - '*'
   pull_request:
+  workflow_dispatch:
 jobs:
   perl:
     runs-on: windows-latest