ci: add workflow_dispatch trigger

.github/workflows/docker-release.yml

@@ -1,6 +1,7 @@
 name: Docker Release
 
 on:
+  workflow_dispatch:
   push:
     tags:
       - "v[0-9]+.[0-9]+.[0-9]+"

.github/workflows/dotnet.yml

@@ -1,6 +1,7 @@
 name: .NET
 
 on:
+  workflow_dispatch:
   push:
   pull_request:
 

.github/workflows/prerelease.yml

@@ -1,6 +1,7 @@
 name: Tagged Pre-Release
 
 on:
+  workflow_dispatch:
   push:
     tags:
       - "v[0-9]+.[0-9]+.[0-9]+-*"

.github/workflows/release.yml

@@ -1,6 +1,7 @@
 name: Tagged Release
 
 on:
+  workflow_dispatch:
   push:
     tags:
       - "v[0-9]+.[0-9]+.[0-9]+"