treewide: update to new multi worker dowork api

The work.Queue() implementation has changed and now allows scheduling
tasks from multiple goroutines in parallel. Also, it requires a new
argument for limiting the queue buffer size in order to apply back
pressure.

Define new configuration variables to allow tuning the queue sizes and
number of workers per service:

  [mail]
  # Maximum size of the outgoing email queue (default 512).
  egress-queue-size = 512

  [$service_name]
  # Number of parallel workers per queue (default 1).
  # There are multiple queues (for egress email, webhooks, etc.).
  # This setting is applied on a per-queue basis.
  queue-workers = 1

  [webhooks]
  # Maximum size of the webhooks queue (default 512).
  queue-size = 512

Use these new settings to configure the queues and workers accordingly.

Fix unit tests as well.

Link: https://git.sr.ht/~sircmpwn/dowork/commit/95719cfc0118
Signed-off-by: Robin Jarry <robin@jarry.cc>

Upgrade Go, `go mod tidy`, build on Alpine 3.20

email: update StartTLS usage per go-smtp changes

Drop gqlparser v1 dependency

Only use v2 throughout the repository.

Migrate to chi v5

v1 is not maintained anymore.

Upgrade dependencies

s3: Import middleware from pages.sr.ht

Closes: https://todo.sr.ht/~sircmpwn/pages.sr.ht/19

go mod tidy

Fixes the following error when running `go test`:

    ../../go/pkg/mod/github.com/prometheus/client_golang@v1.14.0/prometheus/internal/metric.go:19:2: missing go.sum entry for module providing package github.com/prometheus/client_model/go (imported by github.com/prometheus/client_golang/prometheus); to add:
    	go get github.com/prometheus/client_golang/prometheus@v1.14.0

Add prometheus SQL connection stats

Also updates the prometheus client_go library

Update pq (Postgres driver) to latest version

Replace x/crypto package by ProtonMail/go-crypto to support ed25519 OpenPGP keys

Add support for mail setups that don't support TLS or Auth

auth: force webhooks to read-only

auth: fix /query/api-meta.json route

This route does not need authentication.

Update go-bare

Update dependencies

Sign outgoing emails

Update dowork

Add legacy webhooks worker implementation

Expand context for work queues