DevTools Client - Upgrade to 139.0.7258.139

Upgrade to 138.0.34+ga94b31b+chromium-138.0.7204.184 / Chromium 138.0…

….7204.184

DevTools Client - Upgrade to 138.0.7204.97

DevTools - Add ToBase64String not implemented overload to get builds …

…passing.

Will need to be handled at a later time

Core - Update CefErrorCodes (136.0.7103.93) (#5101)

https://raw.githubusercontent.com/chromium/chromium/136.0.7103.93/net/base/net_error_list.h

Test - Disable BrowserRefCount logging

appveyor.yml - Update as release branch

Upgrade to 134.3.9+g5dc6f2f+chromium-134.0.6998.178 / Chromium 134.0.…

…6998.178

Upgrade to 134.3.6+g96006d1+chromium-134.0.6998.118 / Chromium 134.0.…

…6998.118

Tests - Disable GPU Acceleration

There have been transient crashes of the tests when run via Appveyor

https://ci.appveyor.com/project/cefsharp/cefsharp/builds/51568290#L3321