build: T7828: use tomli instead of toml in the package build script

[dmbaturin]

Change summary

Use python3-tomli in the build script. That allows us to get rid of the python3-toml dependency since this is the last place where it was used.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• Other (please describe):

Related Task(s)

Related PR(s)

Checklist:

• I have read the CONTRIBUTING document
• I have linked this PR to one or more Phabricator Task(s)
• My commit headlines contain a valid Task id
• My change requires a change to the documentation
• I have updated the documentation accordingly

[github-actions]

👍
No issues in PR Title / Commit Title

[jestabro]

Use python3-tomli package instead of python3-toml.

[sever-sever]

Build several packages without issues

vyos_bld@7c396283ff2e:/vyos/tmp/vyos-build/scripts/package-build/ethtool$ ls -l
ltotal 1072
lrwxr-xr-x.  1 vyos_bld dialout     11 Oct 22 14:03 build.py -> ../build.py
drwxr-xr-x. 77 vyos_bld dialout   2464 Oct 22 14:06 ethtool
-rw-r--r--.  1 vyos_bld dialout   5438 Oct 22 14:06 ethtool_6.10-1_arm64.buildinfo
-rw-r--r--.  1 vyos_bld dialout   1279 Oct 22 14:06 ethtool_6.10-1_arm64.changes
-rw-r--r--.  1 vyos_bld dialout 200668 Oct 22 14:06 ethtool_6.10-1_arm64.deb
-rw-r--r--.  1 vyos_bld dialout 499688 Oct 22 14:06 ethtool-dbgsym_6.10-1_arm64.deb
-rw-r--r--.  1 vyos_bld dialout 380417 Oct 22 14:05 ethtool_debian_1%6.10-1.tar.gz
-rw-r--r--.  1 vyos_bld dialout    117 Oct 22 14:03 package.toml
vyos_bld@7c396283ff2e:/vyos/tmp/vyos-build/scripts/package-build/ethtool$

---
vyos_bld@7c396283ff2e:/vyos/tmp/vyos-build/scripts/package-build/ddclient$ ls -l
total 468
lrwxr-xr-x.  1 vyos_bld dialout     11 Oct 22 14:03 build.py -> ../build.py
drwxr-xr-x. 32 vyos_bld dialout   1024 Oct 22 14:05 ddclient
-rw-r--r--.  1 vyos_bld dialout 102072 Oct 22 14:05 ddclient_3.11.2-1_all.deb
---
vyos_bld@7c396283ff2e:/vyos/tmp/vyos-build/scripts/package-build/frr$ ls -l
total 47268
lrwxr-xr-x.  1 vyos_bld dialout       11 Oct 22 14:03 build.py -> ../build.py
drwxr-xr-x. 66 vyos_bld dialout     2112 Oct 22 14:16 frr
-rw-r--r--.  1 vyos_bld dialout    11682 Oct 22 14:16 frr_10.2.4-0_arm64.buildinfo
-rw-r--r--.  1 vyos_bld dialout     3927 Oct 22 14:16 frr_10.2.4-0_arm64.changes
-rw-r--r--.  1 vyos_bld dialout  5560868 Oct 22 14:16 frr_10.2.4-0_arm64.deb
-rw-r--r--.  1 vyos_bld dialout 22173612 Oct 22 14:16 frr-dbgsym_10.2.4-0_arm64.deb
-rw-r--r--.  1 vyos_bld dialout  1957976 Oct 22 14:15 frr-doc_10.2.4-0_all.deb
-rw-r--r--.  1 vyos_bld dialout    54480 Oct 22 14:15 frr-pythontools_10.2.4-0_all.deb
-rw-r--r--.  1 vyos_bld dialout    48348 Oct 22 14:15 frr-rpki-rtrlib_10.2.4-0_arm64.deb
-rw-r--r--.  1 vyos_bld dialout    96880 Oct 22 14:15 frr-rpki-rtrlib-dbgsym_10.2.4-0_arm64.deb
...