* Add Yubikey PrivateKey implementation for use by Teleport clients.
- Add yubikey login logic, reusing previously stored private keys.
- Fix identity file decoding with PIV keys, which sign ecdsa certificates.
- Add libpcsclite-dev pre-req for building on linux.
- Remove unnecessary keys.Signer interface and move its functionality to keys.PrivateKey.
- Move retry and jitter utils to new api/utils/retryutils package.
Update metalinter, fix a few lint warnings and replace deprecated linters.
`deadcode`, `structcheck` and `varcheck` are abandoned and now replaced by [`unused`][1].
Since 1.19, `go fmt` reformats godocs according to https://go.dev/doc/comment. I've done a bulk-reformatting of the codebase to keep the linter happy. Backporting is mostly harmless (the exception being `lib/services/role_test.go`, that for some reason breaks the _old_ linter using the new format).
[1]: https://golangci-lint.run/usage/linters/
* Bump golangci-lint version
* Replace abandoned linters
* Fix bodyclose on lib/auth/github.com
* Fix bodyclose on lib/kube/proxy/streamproto/proto_test.go
* Fix bodyclose on lib/srv/alpnproxy/proxy_test.go
* Fix bodyclose on lib/web/conn_upgrade_test.go
* Silence staticcheck on lib/kube/proxy/forwarder_test.go
* Silence staticcheck on lib/utils/certs_test.go
* Address BuildNameToCertificate deprecation warnings
* Run `go fmt ./...`
* Run `go fmt ./...` on api/
* Ignore formatting in role_test.go
* Remove redundant initializers in lib/srv/uacc/
* Update e/
* Add Username to sqlbk and don't leak connConfigs
* Azure AD authentication for sqlbk/Postgres
* Add a Postgres Config test
* Cache Azure tokens, document azureBeforeConnect
* Move the config test to sqlbk
* go mod tidy
* go get azcore azidentity
* configure golangci-lint misspell to check for anglicized spellings
* Americanize spellings
* fix aws constant value with british spelling 🇬🇧
* update api types with americanized spellings
* use american spellings .cloudbuild/scripts