We moved some files further down in the directory structure in #6964, which
caused the relative paths to the mockery wrapper to stop working.
There does not seem to be an obvious way to get the module root as a default
environment variable, so for now I just added the extra up-slashes.
This change aims to keep versions of mockery consistent across developer laptops.
This change adds mockery to the `tools.go` file so that its version can be managed consistently in the `go.mod` file.
Additionally, this change temporarily disables adding mockery's version number to generated files. There is an outstanding issue against the mockery project related to the version string behavior when running from `go get`. I have created a pull request to fix this issue in the mockery project.
see: https://github.com/vektra/mockery/issues/397