Can't install an extension from the embedded openVSX

[svor]

Describe the bug

After switching to the local plugin registry it's not possible to install any extension into Che-Code.
The error message is:

Error while installing 'Go' extension. Please check the log for more details.
onDidChangeNotification @ workbench.web.main.js:808
(anonymous) @ workbench.web.main.js:808
invoke @ workbench.web.main.js:80
deliver @ workbench.web.main.js:80
fire @ workbench.web.main.js:80
addNotification @ workbench.web.main.js:808
notify @ workbench.web.main.js:1996
prompt @ workbench.web.main.js:1996
run @ workbench.web.main.js:3126
install @ workbench.web.main.js:3126
await in install (async)
run @ workbench.web.main.js:3126
run @ workbench.web.main.js:3126
runAction @ workbench.web.main.js:80
run @ workbench.web.main.js:80
onClick @ workbench.web.main.js:174
(anonymous) @ workbench.web.main.js:174
workbench.web.main.js:600   ERR self signed certificate in certificate chain: Error: self signed certificate in certificate chain
    at TLSSocket.onConnectSecure (node:_tls_wrap:1530:34)
    at TLSSocket.emit (node:events:520:28)
    at TLSSocket._finishInit (node:_tls_wrap:944:8)
    at TLSWrap.ssl.onhandshakedone (node:_tls_wrap:725:12)

Che version

next (development version)

Steps to reproduce

1. Update Che CR by setting openVSXURL with empty value to use the embedded plugin registry:

    pluginRegistry:
      openVSXURL: ''

2. Delete dashboard pod because of Dashboard does not respect CheCluster CR changes #21654
3. Start any workspace with Che-Code
4. Try to install any extension

Expected behavior

The extension should be installed

Runtime

OpenShift

Screenshots

Installation method

chectl/next

Environment

Linux

Eclipse Che Logs

No response

Additional context

No response

[benoitf]

looks like an issue on certificates not being trusted

[svor]

@benoitf maybe it'll solve the problem: che-incubator/che-code#96
to use internal plugin registry URL