feat: Update dependency thess/callattendant to v2.1.0

[renovate]

This PR contains the following updates:

Package	Update	Change
thess/callattendant	minor	v2.0.7 -> v2.1.0

---

Release Notes

thess/callattendant (thess/callattendant)

v2.1.0: Callattendant Release v2.1.0

Compare Source

Minor release to introduce an upgraded web server and a couple of fixes.

Changes:

• Replace embedded development WSGI server in Flask with Waitress (asynchronous threads)
  No more Flask dev mode warnings.
• Update NOMOROBO processing to classify current query return data better (@​telnetdoogie)
• Added validation routines to handle CallerID data from modem and drop bogus values instead of crashing. Closes #​64 and #​78

Modem data for CallerID may contain the following fields:
    DATE := 4..6 digit month and day MMDD[YY] (Verify valid month/day values)
    TIME := 4 digit hour and minute HHMM (Verify valid hour/minute values) 
    NMBR := 4..17 digit phone number (required)
    NAME := [optional] 2..15 letters/spaces. Must start with letter.

Installation as an upgrade will install some new dependencies.

---

Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• If you want to rebase/retry this PR, check this box

---

This PR was generated by Mend Renovate. View the repository job log.