Bump MailKit from 3.4.0 to 4.0.0

[dependabot]

Bumps MailKit from 3.4.0 to 4.0.0.

Changelog

Sourced from MailKit's changelog.

MailKit 4.0.0 (2023-04-15)

• Marked the AccessRight and UniqueId structs as readonly.
• Fixed POP3 client logic to calculate the needed bytes before converting commands into into the output buffer.
• Ported to MimeKit v4.0 and BouncyCastle v2.1.1.

MailKit 3.6.0 (2023-03-04)

• Decrement ImapFolder.Count when ImapClient receives an untagged EXPUNGE notification and emit a CountChanged event. (issue #1509)
• Avoid using the NAMESPACE command for Exchange 2003. (issue #1512)
• Added support for rfc8970 (IMAP4 Extension: Message Preview Generation).

MailKit 3.5.0 (2023-01-27)

• Fixed bitmasking logic in SmtpClient.cs for deciding whether to use the BDAT command.
• Fixed HttpProxyClient to call GetConnectCommand() before connecting a socket to prevent memory leaks when connecting fails.
• Improved the IMAP BODYSTRUCTURE parser to better handle broken responses.
• Fixed bug in Envelope.Parse/TryParse when given (NIL NIL "" "localhost") (issue #1471)
• Fixed SMTP client logic to calculate the needed bytes before converting commands into into the output buffer. (issue #1498)
• Fixed SmtpClient to replace _'s with -'s in the default LocalDomain string (used in HELO/EHLO commands). (issue #1501)

MailKit 3.4.3 (2022-11-25)

• Fixed potential memory leaks in Pop3Client.
• Reverted SMTP pipelining of the DATA command. (issue #1459)
• Fixed ImapFolder.Rename() to disallow renaming a folder to be a child of itself.
• Fixed SmtpStream.ReadResponse/Async() to handle buffers that do not contain a complete line. (issue #1467)

MailKit 3.4.2 (2022-10-24)

• Fixed fetching of MessageSummaryItems.PreviewText if the octet count of the message body is 0. (issue #1430)
• Modified ImapFolder.Search(SearchOptions.None, query) work the same as ImapFolder.Search(query). (issue #1437)
• Improved performance of SmtpClient by reducing memory allocations and pipelining the DATA command when the PIPELINING extension is available.
• Refactored sync and async SmtpClient APIs such that the synchronous APIs no longer call methods marked with async in order to reduce AsyncMethodBuilder state machines/allocations.
• Modified SmtpClient to only send the ORCPT argument to RCPT TO if NOTIFY is specified.
• Improved performance of Pop3Client by reducing memory allocations.
• Refactored sync and async Pop3Client APIs such that the synchronous APIs no longer call methods marked with async in order to reduce AsyncMethodBuilder state machines/allocations.
• Improved IMAP's BODY/BODYSTRUCTURE parser to be able to scan ahead multiple tokens in order to better handle syntactically

... (truncated)

Commits

• 504b796 Bumped version to 4.0.0
• 27c4821 Generate MailKit.dll.config (assembly redirects) and include in the nugets
• 20e041d Fixed MD4 to only dispose internal buffers if disposing == true
• 99576c4 Updated ReleaseNotes.md
• cb645cf Ignore some code analysis warnings
• 1311ece Updated SSL certificates
• e303448 Calculate needed bytes before converting into the output buffer
• cf6c5e8 code modernization
• 6fde383 Added unit tests for issue #1536
• 98d0068 Disable some warnings in the UnitTests
• Additional commits viewable in compare view

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