fix: fix skip-install option to bootstrap command

Updated the bootstrap process to allow users to bypass the installation
check. This change prevented the command from failing when Pipelines as
Code is already present in the cluster, enabling users to skip the
automatic installation step when it is not required.

Closes #2708

Author: chmouel

pkg/cmd/tknpac/bootstrap/bootstrap.go

@@ -207,7 +207,7 @@ func GithubApp(run *params.Run, ioStreams *cli.IOStreams) *cobra.Command {
 				return err
 			}
 			// installed but there is error for missing resources
-			if installed && !opts.forceInstall {
+			if installed && !opts.forceInstall && !opts.skipInstall {
 				return fmt.Errorf("pipelines as Code is already installed, please pass --force-install to override existing")
 			}