os/exec: include Cmd.Start in the list of methods that run Cmd

Fixes #76265

Change-Id: I451271c5662dd3bcdeec07b55761b15f64c00dcd
Reviewed-on: https://go-review.googlesource.com/c/go/+/719860
Reviewed-by: Keith Randall <[email protected]>
Reviewed-by: Alan Donovan <[email protected]>
Auto-Submit: Keith Randall <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Keith Randall <[email protected]>

Author: seankhliao

src/os/exec/exec.go

@@ -142,8 +142,8 @@ func (w wrappedError) Unwrap() error {
 
 // Cmd represents an external command being prepared or run.
 //
-// A Cmd cannot be reused after calling its [Cmd.Run], [Cmd.Output] or [Cmd.CombinedOutput]
-// methods.
+// A Cmd cannot be reused after calling its [Cmd.Start], [Cmd.Run],
+// [Cmd.Output], or [Cmd.CombinedOutput] methods.
 type Cmd struct {
 	// Path is the path of the command to run.
 	//