There's little to no added value for UTF-8 in this file, while some
editors do cause trouble when editing those files (e.g. adding BOM
on Windows). This just avoids that hassle where we can.

Closes: #1432

Closes: #1430
(cherry picked from commit 94d08530)

Commit 1edc1264 replaced Travis CI with GitHub Actions. These are
configured through the `.github` directory.

(cherry picked from commit b09c98e1)

Commit 1edc1264 replaced Travis CI with GitHub Actions. Remove the
remaining references to Travis CI.

(cherry picked from commit 4ce4c737)

(cherry picked from commit acbbef76)

(cherry picked from commit 879588a5)

(cherry picked from commit 3a707ec6)