Updated nss and firefox packages fix security vulnerabilities

The updated packages fix security vulnerabilities Heap-buffer-overflow affecting WebGL DrawElementsInstanced method with Mesa VM driver. (CVE-2023-6856) Potential exposure of uninitialized data in EncryptingOutputStream. (CVE-2023-6865) Symlinks may resolve to smaller than expected buffers. (CVE-2023-6857) Heap buffer overflow in nsTextFragment. (CVE-2023-6858) Use-after-free in PR_GetIdentitiesLayer. (CVE-2023-6859) Potential sandbox escape due to VideoBridge lack of texture validation. (CVE-2023-6860) Clickjacking permission prompts using the popup transition. (CVE-2023-6867) Heap buffer overflow affected nsWindow::PickerOpen(void) in headless mode. (CVE-2023-6861) Use-after-free in nsDNSService. (CVE-2023-6862) Undefined behavior in ShutdownObserver(). (CVE-2023-6863) Memory safety bugs fixed in Firefox 121, Firefox ESR 115.6, and Thunderbird 115.6. (CVE-2023-6864)