Restore local DNS caching

This reverts commit 543eb178.

Restores the dns caching configuration that should be feasible, since we
now require around 8 MB of flash.

We migrate to dnsmasq-full, while disabling most of its features.
Notably, dhcp and dnssec are compiled in, while other features of the
full variant are deselected.

workflows/docker: bump editorconfig-checker from 2.6.0 to 2.7.0

- [Release notes](https://github.com/editorconfig-checker/editorconfig-checker/releases)
- [Commits](https://github.com/editorconfig-checker/editorconfig-checker/compare/2.6.0...2.7.0

)

Signed-off-by: Jan-Niklas Burfeind <git@aiyionpri.me>

actions: add editorconfig checker

- [*.mk]
- [Makefile]

OpenWrt and Gluon use spaces for a better overview,
tabs are used for `make` to mark recipes as such.

Co-authored-by: Jan-Niklas Burfeind <git@aiyionpri.me>
version bump to 2.6.0
aligned indentation

Adds `lint-editorconfig` make target.

Co-authored-by: Jan-Niklas Burfeind <git@aiyionpri.me>
version bump to 2.6.0

C indentation

Editorconfig leftovers

found BSD-2-Clause

found BSD-2-Clause

migrate several c files to spdx

ramips-mt7621: add TP-Link Archer C6 v3

Fix some typos (found by codespell)

Signed-off-by: Stefan Weil <sw@weilnetz.de>