ci: update CI workflow to handle optional inputs

Set default values to false for optional inputs in CI workflow.

Author: haithium

.github/workflows/ci.yml

@@ -66,12 +66,12 @@ jobs:
       macos:   ${{ inputs.macos   || github.event_name != 'workflow_dispatch' }}
       windows: ${{ inputs.windows || github.event_name != 'workflow_dispatch' }}
 
-      stylua:       ${{ inputs.stylua       }}
-      luacheck:     ${{ inputs.luacheck     }}
-      markdownlint: ${{ inputs.markdownlint }}
+      stylua:       ${{ inputs.stylua       || false }}
+      luacheck:     ${{ inputs.luacheck     || false }}
+      markdownlint: ${{ inputs.markdownlint || false }}
 
-      tests: ${{ inputs.tests }}
-      docs:  ${{ inputs.docs  }}
+      tests: ${{ inputs.tests || false }}
+      docs:  ${{ inputs.docs  || false }}
 
-      release-please:  ${{ inputs.release-please  }}
-      luarocks-upload: ${{ inputs.luarocks-upload }}
+      release-please:  ${{ inputs.release-please  || false }}
+      luarocks-upload: ${{ inputs.luarocks-upload || false }}