Cleanup: pass submittedJob as pointer to two-way variable replacer

The two-way variable replacement function changes the submitted job. To
clarify that this happens, pass the pointer `&submittedJob`.

Both pass-by-pointer and pass-by-value work, because the variable
replacement typically works on maps/slices, which are passed by reference
anyway. Better to be explicit about this, though.

No functional changes.

internal/manager/api_impl/jobs.go

@@ -89,7 +89,7 @@ func (f *Flamenco) SubmitJob(e echo.Context) error {
 
 	// Before compiling the job, replace the two-way variables. This ensures all
 	// the tasks also use those.
-	replaceTwoWayVariables(f.config, submittedJob)
+	replaceTwoWayVariables(f.config, &submittedJob)
 
 	authoredJob, err := f.jobCompiler.Compile(ctx, submittedJob)
 	switch {

internal/manager/api_impl/varrepl.go

@@ -77,7 +77,7 @@ func replaceTaskVariables(replacer VariableReplacer, task api.AssignedTask, work
 // `{render}/output.png`
 //
 // NOTE: this updates the job in place.
-func replaceTwoWayVariables(replacer VariableReplacer, job api.SubmittedJob) {
+func replaceTwoWayVariables(replacer VariableReplacer, job *api.SubmittedJob) {
 	feeder := make(chan string, 1)
 	receiver := make(chan string, 1)
 

internal/manager/api_impl/varrepl_test.go

@@ -197,7 +197,7 @@ func TestReplaceTwoWayVariables(t *testing.T) {
 		replaced := varReplSubmittedJob()
 		replaced.Settings = nil
 		replaced.Metadata = nil
-		replaceTwoWayVariables(&c, replaced)
+		replaceTwoWayVariables(&c, &replaced)
 
 		assert.Equal(t, original.Type, replaced.Type, "two-way variable replacement shouldn't happen on the Type property")
 		assert.Equal(t, original.Name, replaced.Name, "two-way variable replacement shouldn't happen on the Name property")
@@ -211,7 +211,7 @@ func TestReplaceTwoWayVariables(t *testing.T) {
 	{
 		original := varReplSubmittedJob()
 		replaced := jsonWash(varReplSubmittedJob())
-		replaceTwoWayVariables(&c, replaced)
+		replaceTwoWayVariables(&c, &replaced)
 
 		expectSettings := map[string]interface{}{
 			"blender_cmd":           "{blender}",