all: update the x/tools dependency to fix the build with Go 1.25 (#432)

An unfortunate bug caused a number of packages in old x/tools versions
to fail to build with Go 1.25 (https://go.dev/issue/74462). Fix this
minimally by updating to the lowest patched version with the fix:
v0.24.1. This should allow wire to continue building with the same range
of Go versions as it could build with before (down to 1.19).

Also:
- Update the go.mod go directive to Go 1.19 to allow for module graph
  pruning, and to be consistent with the minimum build version.
- Fix a test that is broken in recent Go versions due to an error
  message change.
- Update tests to run on Go 1.25.x (the most recent version of Go).
- Remove coverage, since coverage upload wasn't working anyway.

Fixes #431

README.md

@@ -2,7 +2,6 @@
 
 [![Build Status](https://github.com/google/wire/actions/workflows/tests.yml/badge.svg?branch=main)](https://github.com/google/wire/actions)
 [![godoc](https://godoc.org/github.com/google/wire?status.svg)][godoc]
-[![Coverage](https://codecov.io/gh/google/wire/branch/master/graph/badge.svg)](https://codecov.io/gh/google/wire)
 
 
 Wire is a code generation tool that automates connecting components using