CAMEL-19012: Remove Camel v2 documentation

[essobedo]

Fixes https://issues.apache.org/jira/browse/CAMEL-19012

Motivation

Camel 2 is EOL a long time and should be removed to speed up a bit the website build

Modifications:

• Removes Camel v2 documentation

[essobedo]

The errors don't seem to be related:

➤ YN0000: [build:antora  ] [build:antora-perf] [10:30:05.025] ERROR (asciidoctor): target of xref not found: 4.0.x@camel-kamelets:ROOT:index.adoc
➤ YN0000: [build:antora  ] [build:antora-perf]     file: docs/modules/ROOT/pages/index.adoc
➤ YN0000: [build:antora  ] [build:antora-perf]     source: https://github.com/apache/camel-k.git (refname: main, start path: docs)
➤ YN0000: [build:antora  ] [build:antora-perf] [10:30:11.178] ERROR (asciidoctor): target of xref not found: 4.0.x@camel-kamelets:ROOT:index.adoc
➤ YN0000: [build:antora  ] [build:antora-perf]     file: docs/modules/ROOT/pages/index.adoc
➤ YN0000: [build:antora  ] [build:antora-perf]     source: https://github.com/apache/camel-k.git (refname: release-1.10.x, start path: docs)
➤ YN0000: [build:antora  ] [build:antora-perf] [10:30:16.482] ERROR (asciidoctor): target of xref not found: 4.0.x@camel-kamelets:ROOT:index.adoc
➤ YN0000: [build:antora  ] [build:antora-perf]     file: docs/modules/ROOT/pages/index.adoc
➤ YN0000: [build:antora  ] [build:antora-perf]     source: https://github.com/apache/camel-k.git (refname: release-1.11.x, start path: docs)
➤ YN0000: [build:antora  ] [build:antora-perf] [10:30:21.780] ERROR (asciidoctor): target of xref not found: 4.0.x@camel-kamelets:ROOT:index.adoc
➤ YN0000: [build:antora  ] [build:antora-perf]     file: docs/modules/ROOT/pages/index.adoc
➤ YN0000: [build:antora  ] [build:antora-perf]     source: https://github.com/apache/camel-k.git (refname: release-1.12.x, start path: docs)
➤ YN0000: [build:antora  ] [build:antora-perf] [10:30:[27](https://github.com/apache/camel-website/actions/runs/5713327304/job/15478528911#step:4:28).302] ERROR (asciidoctor): target of xref not found: 4.0.x@camel-kamelets::index.adoc
➤ YN0000: [build:antora  ] [build:antora-perf]     file: docs/modules/ROOT/pages/index.adoc
➤ YN0000: [build:antora  ] [build:antora-perf]     source: https://github.com/apache/camel-k.git (refname: release-2.0.x, start path: docs)
➤ YN0000: [build:antora  ] [build:antora-perf] [10:30:27.308] ERROR (asciidoctor): target of xref not found: 4.0.x@camel-kamelets:ROOT:index.adoc
➤ YN0000: [build:antora  ] [build:antora-perf]     file: docs/modules/ROOT/pages/index.adoc
➤ YN0000: [build:antora  ] [build:antora-perf]     source: https://github.com/apache/camel-k.git (refname: release-2.0.x, start path: docs)