Fix proxy errors during CSA

[thc202]

The proxy that the browser was using could be closed too early when used by Client Script Based Authentication, which could try refresh the page after authentication to trigger more requests and increase the likelihood of obtaining a verification URL.

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Fixes exceptions like:

ERROR User - An error occurred while authenticating:
org.openqa.selenium.WebDriverException: Reached error page: about:neterror?e=proxyConnectFailure&u=…&c=UTF-8&d=Firefox%20is%20configured%20to%20use%20a%20proxy%20server%20that%20is%20refusing%20connections.
Build info: version: '4.35.0', revision: '1c58e5028b'
System info: os.name: 'Linux', os.arch: 'amd64', os.version: '…', java.version: '…'
Driver info: org.openqa.selenium.firefox.FirefoxDriver
Command: [d0c87c9e-457f-4d7b-8840-25d531f8f779, get {url=…}]
Capabilities {…}
Session ID: d0c87c9e-457f-4d7b-8840-25d531f8f779
	at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(Unknown Source) ~[?:?]
	at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Unknown Source) ~[?:?]
	at java.base/java.lang.reflect.Constructor.newInstance(Unknown Source) ~[?:?]
	at org.openqa.selenium.remote.ErrorCodec.decode(ErrorCodec.java:167) ~[?:?]
	at org.openqa.selenium.remote.codec.w3c.W3CHttpResponseCodec.decode(W3CHttpResponseCodec.java:138) ~[?:?]
	at org.openqa.selenium.remote.codec.w3c.W3CHttpResponseCodec.decode(W3CHttpResponseCodec.java:50) ~[?:?]
	at org.openqa.selenium.remote.HttpCommandExecutor.execute(HttpCommandExecutor.java:215) ~[?:?]
	at org.openqa.selenium.remote.service.DriverCommandExecutor.invokeExecute(DriverCommandExecutor.java:216) ~[?:?]
	at org.openqa.selenium.remote.service.DriverCommandExecutor.execute(DriverCommandExecutor.java:174) ~[?:?]
	at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:557) ~[?:?]
	at org.openqa.selenium.remote.RemoteWebDriver.get(RemoteWebDriver.java:325) ~[?:?]
	at org.zaproxy.addon.authhelper.ClientScriptBasedAuthenticationMethodType$ClientScriptBasedAuthenticationMethod.authenticate(ClientScriptBasedAuthenticationMethodType.java:512) ~[?:?]
	at org.zaproxy.zap.users.User.authenticate(User.java:271) [zap-D-2025-08-18.jar:D-2025-08-18]

[psiinon]

Checkmarx One – Scan Summary & Details – 28532e37-692f-4932-aeef-e4d4c6677634

Great job! No new security vulnerabilities introduced in this pull request