Upgrade golangci-lint (#182)

1.42 seems to be having some problems with Go 1.18 (see #2649), so let's
just upgrade to latest.  There was one new error, suggesting to use `%q`
rather than `"%s"`, since the former does escapes properly.  It doesn't
really matter for us -- the string should be an identifier -- but it
doesn't hurt.  (Plus it wanted us to upgrade from ioutil, which I did
in #181.)

Test plan: make check

generate/types.go

@@ -484,7 +484,7 @@ func (typ *goInterfaceType) WriteDefinition(w io.Writer, g *generator) error {
 					"(see interface doc for possible values).", methodName)
 		} else {
 			description = fmt.Sprintf(
-				`%s returns the interface-field "%s" from its implementation.`,
+				`%s returns the interface-field %q from its implementation.`,
 				methodName, sharedField.GraphQLName)
 			if sharedField.Description != "" {
 				description = fmt.Sprintf(