Commit 4cae6a72 introduced the message,
but it printed the wrong path, e.g. for `brew link sqlite`:

```
If you need to have this software first in your PATH instead consider running:
  echo 'export PATH="/usr/local/opt/sqlite:$PATH"' >> ~/.zshrc/bin
```

where `/bin` is appended at the end, but should be inserted before
`:$PATH`: `echo 'export PATH="/usr/local/opt/sqlite/bin:$PATH"' >> ~/.zshrc`.
This patch fixes that and updates a test to verify it.

Fixes #2427.

Otherwise we could end up removing files unnecessarily.

This avoids needing to use `force: true` and still let's Homebrew do
what we want with our own taps.

Migrate between different taps and delete relevant subdirectories if
they can be safely. Also, tweak some naming and use utility methods.

Use `oh1` for moving kegs to a new directory.

Move the checks for moving kegs to a new directory into the relevant
method (`move_to_new_directory`) instead. Also, delete duplicated
directories when we’ve confirmed they are definitely duplicated rather
than telling users to do so.

Add methods to determine if a migration is needed and perform it if so
(and no-op if not). Additionally, make `ARGV.force?` get passed as a
parameter so it can be overridden without requiring users to pass
`—force`.

Fixes #2355
Create unremovable_kegs instance var
Check cellar cleanup failure after full cleanup completes
Use module_function in Homebrew::Cleanup as we never instantiate the
class

Otherwise return `nil`.

Fixes https://github.com/Homebrew/brew/issues/2417

Need to check for two `/`s rather than one.

We could try and get a partial result but given it'll also be wrong it
feels simpler to just return an empty array.

Fixes #1928.
Fixes #2027.
Closes #2058.
Fixes https://github.com/Homebrew/homebrew-core/issues/11827.

Additionally, ignore the cctools formula itself, since it obviously
needs to check cctools invocations.

Test the situation where a requirement is satisfied by a non-formula
but the `default_formula` is also installed.

Use git fetch --tags --depth=1 to fetch fewer commits.

older versions do not support the 'git -C <path>' option

Fail if the start or end commit are missing and retry finding the
previous tag by fetching all tags if they are missing.

This should fix CI on the current Homebrew/brew `master` branch.

Closes #2404.

The structure should be consistent, so there are always pinned and
pinned_version fields even if there are no pinned versions for a given formula.

Split the tests up into quiet and verbose output with contexts.

If we're adding a versioned formulae we want to ensure that there's also
an unversioned one too.

Check the remote for homebrew/core as well as homebrew/brew as we've
seen a few cases (e.g. #2387) where it was misconfigured.

While we're here, tweak the messaging to tell people what to do and how
to do so with a single command.

- Remove taps that are (or will shortly be) deprecated.
- Remove commands that are only relevant to the boneyard (which will
  shortly be removed).