Upgrade tokenizers dependency to get rid of CVE-2026-4539

[Realiserad]

Describe the improvement

cohere==5.20.7 is pulling pygments 2.19.2 which has a CVE.

Found 1 known vulnerability in 1 package
Name     Version ID            Fix Versions
-------- ------- ------------- ------------
pygments 2.19.2  CVE-2026-4539

Pygments==2.19.2
└── rich==14.3.3 [requires: Pygments>=2.13.0,<3.0.0]
    └── typer==0.24.1 [requires: rich>=12.3.0]
        └── huggingface_hub==1.6.0 [requires: typer]
            └── tokenizers==0.22.2 [requires: huggingface_hub>=0.16.4,<2.0]
                └── cohere==5.20.7 [requires: tokenizers>=0.15,<1]

[mkozakov]

Fixed here: #747