ci - use github actions checkout@v4 instead of v2

Merge branch 'bump-version' into master

Merge branch 'tcp-bugfix-decoder' into 'master'

TCP input: fix bug when detecting decoder of connection

See merge request monitoring/ipfixcol2!19

CMake: bump collector version to 2.6.0

CMake: bump collector version to 2.4.1

CMake: bump collector version to 2.4.0

Merge pull request #63 from CESNET/devel

Merge devel to master and bump version to 2.3.0

Merge pull request #17 from CESNET/devel

Merge devel into master

IPFIXcol version 2.0.0