Allow manual execution of GitHub workflows

.github/workflows/presubmit-c.yml

@@ -4,6 +4,7 @@
     branches: ['master']
   pull_request:
     branches: ['master']
+  workflow_dispatch: {}
 
 jobs:
   clang-format:
@@ -44,7 +45,7 @@
         nix_path: nixpkgs=channel:nixos-unstable
     - name: install Nix dependencies
       if: ${{ matrix.container == null }}
       run: nix-shell --run 'meson --buildtype=release --werror build && ninja -C build && meson test --print-errorlogs -C build'
     - name: setup build directory
       if: ${{ matrix.container != null }}
       run: meson --werror build

.github/workflows/presubmit-go.yml

@@ -4,6 +4,7 @@ on:
     branches: ['master']
   pull_request:
     paths: ['go/**', '.github/workflows/presubmit-go.yml']
+  workflow_dispatch: {}
 
 defaults:
   run:

.github/workflows/presubmit-python.yml

@@ -4,6 +4,7 @@ on:
     branches: ['master']
   pull_request:
     paths: ['python/**', '.github/workflows/presubmit-python.yml']
+  workflow_dispatch: {}
 
 defaults:
   run:

.github/workflows/presubmit-rust.yml

@@ -4,6 +4,7 @@ on:
     branches: ['master']
   pull_request:
     paths: ['rust/**', '.github/workflows/presubmit-rust.yml']
+  workflow_dispatch: {}
 
 defaults:
   run:

.github/workflows/presubmit-shell.yml

@@ -4,6 +4,7 @@ on:
     branches: ['master']
   pull_request:
     paths: ['**.sh', '.github/workflows/presubmit-shell.yml']
+  workflow_dispatch: {}
 
 jobs:
   shellcheck:

.github/workflows/presubmit-yaml.yml

@@ -4,6 +4,7 @@ on:
     branches: ['master']
   pull_request:
     paths: ['**.yml', '**.yaml']
+  workflow_dispatch: {}
 
 jobs:
   lint: