Apart from flipping all version references, a few other upgrades took place:
The old github.com/matryer/moq wasn't compatible with newer Go versions. This resulted in some whitespace changes in the generated files.
An execution of "go fix" changed the build tag in a few files from the old "// +build foo" to the newer "//go:build foo".
golangci-lint had to be upgraded to the newest version. In the new version, three linters we'd enabled had been removed so we had to remove them from the configuration.
Now that testing.T has a method for creating temporary directories, all tests creating such directories by other means have been rewritten.
All references to the deprecated io/ioutil package have been replaced.
Apart from flipping all version references, a few other upgrades took place: