fix(deps): update dependency phpseclib/phpseclib to v3.0.21 - autoclosed

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
phpseclib/phpseclib (source)	require	patch	3.0.19 -> 3.0.21

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Release Notes

phpseclib/phpseclib (phpseclib/phpseclib)

### [`v3.0.21`](https://togithub.com/phpseclib/phpseclib/blob/HEAD/CHANGELOG.md#3021---2023-07-09) [Compare Source](https://togithub.com/phpseclib/phpseclib/compare/3.0.20...3.0.21) - BigInteger: speed up powMod() method ([#​1919](https://togithub.com/phpseclib/phpseclib/issues/1919)) - SSH2: fix stream_select(): Unable to select \[4]: Interrupted system call (max_fd=29) error ([#​1851](https://togithub.com/phpseclib/phpseclib/issues/1851)) - SSH2: add EOF test isConnected() ([#​1926](https://togithub.com/phpseclib/phpseclib/issues/1926)) - SFTP: make it so SFTP::RESUME also sets offset of local file ([#​1921](https://togithub.com/phpseclib/phpseclib/issues/1921)) - SFTP: SFTP::RESUME_START didn't work as described ([#​1921](https://togithub.com/phpseclib/phpseclib/issues/1921)) ### [`v3.0.20`](https://togithub.com/phpseclib/phpseclib/blob/HEAD/CHANGELOG.md#3020---2023-06-13) [Compare Source](https://togithub.com/phpseclib/phpseclib/compare/3.0.19...3.0.20) - SSH2: better support for multiple interactive channels & expose shell functions ([#​1888](https://togithub.com/phpseclib/phpseclib/issues/1888)) - SFTP: add optional $recursive parameter to filesize() ([#​1782](https://togithub.com/phpseclib/phpseclib/issues/1782)) - SFTP: fix NET_SFTP_ATTR_EXTENDED ([#​1907](https://togithub.com/phpseclib/phpseclib/issues/1907)) - ASN1: speed up decodeBER ([#​1894](https://togithub.com/phpseclib/phpseclib/issues/1894)) - X509: add support for EV DN's ([#​1916](https://togithub.com/phpseclib/phpseclib/issues/1916)) - X509: getChain() should always return array of X509 objects ([#​1914](https://togithub.com/phpseclib/phpseclib/issues/1914)) - RSA: setting sig padding broke enc padding and vice versa

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Configuration

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