doc: fix various typos

Found via `codespell -q 3 -L atleast,iinclude,ist,programm,reenable,ser,uptodate`

cmd/restic/global.go

@@ -43,7 +43,7 @@ import (
 	"golang.org/x/term"
 )
 
-// ErrNoRepository is used to report if opening a repsitory failed due
+// ErrNoRepository is used to report if opening a repository failed due
 // to a missing backend storage location or config file
 var ErrNoRepository = errors.New("repository does not exist")
 

cmd/restic/main.go

@@ -174,7 +174,7 @@ func main() {
 	if err == nil {
 		err = ctx.Err()
 	} else if err == ErrOK {
-		// ErrOK overwrites context cancelation errors
+		// ErrOK overwrites context cancellation errors
 		err = nil
 	}