cli/context: ignore linting warnings about RFC 1423 encryption

From https://go-review.googlesource.com/c/go/+/264159

> It's unfortunate that we don't implement PKCS#8 encryption so we can't
> recommend an alternative but PEM encryption is so broken that it's worth
> deprecating outright.

When linting on Go 1.16:

    cli/context/docker/load.go:69:6: SA1019: x509.IsEncryptedPEMBlock is deprecated: Legacy PEM encryption as specified in RFC 1423 is insecure by design. Since it does not authenticate the ciphertext, it is vulnerable to padding oracle attacks that can let an attacker recover the plaintext.  (staticcheck)
            if x509.IsEncryptedPEMBlock(pemBlock) {
               ^
    cli/context/docker/load.go:70:20: SA1019: x509.DecryptPEMBlock is deprecated: Legacy PEM encryption as specified in RFC 1423 is insecure by design. Since it does not authenticate the ciphertext, it is vulnerable to padding oracle attacks that can let an attacker recover the plaintext.  (staticcheck)
                keyBytes, err = x509.DecryptPEMBlock(pemBlock, []byte(c.TLSPassword))
                                ^

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 2688f25)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/context/docker/load.go

@@ -66,8 +66,9 @@ func (c *Endpoint) tlsConfig() (*tls.Config, error) {
 		}
 
 		var err error
-		if x509.IsEncryptedPEMBlock(pemBlock) {
-			keyBytes, err = x509.DecryptPEMBlock(pemBlock, []byte(c.TLSPassword))
+		// TODO should we follow Golang, and deprecate RFC 1423 encryption, and produce a warning (or just error)? see https://github.com/docker/cli/issues/3212
+		if x509.IsEncryptedPEMBlock(pemBlock) { //nolint: staticcheck // SA1019: x509.IsEncryptedPEMBlock is deprecated, and insecure by design
+			keyBytes, err = x509.DecryptPEMBlock(pemBlock, []byte(c.TLSPassword)) //nolint: staticcheck // SA1019: x509.IsEncryptedPEMBlock is deprecated, and insecure by design
 			if err != nil {
 				return nil, errors.Wrap(err, "private key is encrypted, but could not decrypt it")
 			}