fix(deps): update dependency postmark to v4

[renovate]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
postmark (source)	2.9.5 -> 4.0.5

---

Release Notes

ActiveCampaign/postmark.js (postmark)

v4.0.5

Compare Source

• update axios to 1.7.4

v4.0.4

Compare Source

• update axios to 1.7.2

v4.0.3

Compare Source

• updated models to support adding content disposition to attachments
• update domain model

v4.0.2

Compare Source

• updated models to be more accurate mostly within webhook payloads area

v4.0.1

Compare Source

• update development libraries

v4.0.0

Compare Source

• dropped support for older EOL Node JS versions, minimum supported Node version is 14.0.0
• updated axios to the version 1.6.2

v3.11.0

Compare Source

• added filtering to get suppressions endpoint

v3.1.2

Compare Source

• add content type header to the http client default headers list

v3.1.1

Compare Source

• small naming update for data removal endpoints

v3.1.0

Compare Source

• added data removal endpoints

v3.0.20

Compare Source

• small fix to webhook types model

v3.0.19

Compare Source

• updated model to contain webhook types

v3.0.18

Compare Source

• fix domain endpoint request types

v3.0.17

Compare Source

• updated test library versions
• switched from nconf to dotenv for configuration loading for tests

v3.0.16

Compare Source

v3.0.15

Compare Source

• added Sanboxed field to the outbound message model
• fix parsing bounced messages

v3.0.14

Compare Source

• Updated statistics filtering parameter

v3.0.13

Compare Source

• Minor code fix, fixing up library versions for older versions of node

v3.0.12

Compare Source

• Migrated to ActiveCampaign

v3.0.11

Compare Source

• Small bug fix to data model

v3.0.1

Compare Source

• updated model to contain webhook types

v3.0.0

Compare Source

• Updated message response for sending
• Decoupled and refactored http client part of the library

---

Configuration

📅 Schedule: Branch creation - "before 4am on Monday" (UTC), 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.