feat: Add GSSAPI/Kerberos (SPNEGO) support to libcurl build

[bararchy]

Summary

Enable Kerberos/SPNEGO authentication (Negotiate) on Linux by adding the gssapi vcpkg feature to the curl build.

Related: NeuraLegion/bright-cli#751 (adds --kerberos CLI flag to bright-cli repeater)

Changes

vcpkg.template.json

Added "gssapi" to curl features list. This tells vcpkg to build curl with --with-gssapi, enabling CURLAUTH_NEGOTIATE on Linux/macOS.

.github/actions/install-system-packages/action.yaml

Added system Kerberos development libraries needed for vcpkg to link against:

• Alpine: krb5-dev
• Ubuntu: libkrb5-dev
• macOS: Not needed (GSS.framework is built-in)

Effect

After this change + new prebuilt release, Curl.getVersion() will include GSS-API in the features list, and curl.setOpt("HTTPAUTH", CurlAuth.Negotiate) will work on Linux.

Verification

const { Curl } = require("@brightsec/node-libcurl");
console.log(Curl.getVersion());
// Before: libcurl/8.17.0 OpenSSL/3.5.6 zlib/1.3.1 brotli/1.2.0 ...
// After:  libcurl/8.17.0 OpenSSL/3.5.6 zlib/1.3.1 brotli/1.2.0 ... GSS-API ...