modify upstream workflows to trigger on workflow dispatch instead of all PRs

.github/workflows/c-cpp.yml

@@ -1,11 +1,8 @@
 name: C/C++ CI
 
 on:
-  push:
-    paths: [ '**.c', '**.h', '**.m4', '**.sh', '.github/**', '**/Makefile.in', 'configure.ac' ]
-  pull_request:
-    paths: [ '**.c', '**.h', '**.m4', '**.sh', '.github/**', '**/Makefile.in', 'configure.ac' ]
-
+  workflow_dispatch:
+  
 jobs:
   ci:
     if: github.repository != 'openssh/openssh-portable-selfhosted'

.github/workflows/cifuzz.yml

@@ -1,9 +1,6 @@
 name: CIFuzz
 on:
-  push:
-    paths: [ '**.c', '**.h', '**.m4', '**.sh', '.github/**', '**/Makefile.in', 'configure.ac' ]
-  pull_request:
-    paths: [ '**.c', '**.h', '**.m4', '**.sh', '.github/**', '**/Makefile.in', 'configure.ac' ]
+  workflow_dispatch:
 
 jobs:
   Fuzzing:

.github/workflows/selfhosted.yml

@@ -1,8 +1,7 @@
 name: C/C++ CI self-hosted
 
 on:
-  push:
-    paths: [ '**.c', '**.h', '**.m4', '**.sh', '.github/**', '**/Makefile.in', 'configure.ac' ]
+  workflow_dispatch:
 
 jobs:
   selfhosted: