CI/Docs: remove non-needed build jobs in documentation pipelines

Relates to #8170

What

Removes from the needs of [documentation.manuals] the two build job [oc.build_amd64-exp] and [oc.build_kernels].

Why

Because the documentation.manuals runs make -C docs -j octez-gen

According to docs/Makefile are needed:

• octez-node (developer/metrics.csv target)
• octez-smart-rollup-node (developer/rollup_metrics.csv target)
• octez-admin-client, octez-signer, octez-codec, octez-snoop, octez-smart-rollup-node, octez-node, octez-baker, octez-accuser, octez-dal-node.

Artifacts produced by oc.build_kernels are:

• evm_kernel.wasm
• smart-rollup-installer
• sequenced_kernel.wasm
• tx_kernel.wasm
• tx_kernel_dal.wasm
• dal_echo_kernel.wasm

Artifacts produced by oc.build_amd64-exp are listed in script-inputs/experimental-executables

etherlink-governance-observer
octez-evm-node
octez-accuser-alpha
octez-baker-alpha
octez-teztale-snitch
octez-teztale-archiver
octez-teztale-server

How

• Remove the jobs from the needs_legacy (job) and legacy_jobs (pipeline registration) and generate YAML.

Manually testing the MR

• make -C ci check should pass.

• review the yaml diff

• documentation.update test pipeline: https://gitlab.com/tezos/tezos/-/pipelines/2224309611 (red because the pipeline does not run on master a protected branch (some env var missing)).

• Review the doc diff:

Compare the artefacts of the latest documentation.build_all from master (job 12497863614) with those of documentation.build_all on this MR branch (job 12497192126).

I've used a script that is attached here (doc_diff_script.sh). It generated this diff (folder_comparison_12497863614_12497192126_summary.diff).

The diff contains mostly mundane content such as

############################################################
## DIFF for: docs/_build/tallinn/blocks_ops.html
############################################################
--- 12497863614/docs/_build/tallinn/blocks_ops.html	2025-12-19 13:25:20
+++ 12497192126/docs/_build/tallinn/blocks_ops.html	2025-12-19 12:36:52
@@ -45,7 +45,7 @@

     <script src="../_static/jquery.js?v=5d32c60e"></script>
     <script src="../_static/_sphinx_javascript_frameworks_compat.js?v=2cd50e6c"></script>
-    <script src="../_static/documentation_options.js?v=f624d00e"></script>
+    <script src="../_static/documentation_options.js?v=fe51d915"></script>
     <script src="../_static/doctools.js?v=9a2dae69"></script>
     <script src="../_static/sphinx_highlight.js?v=dc90522c"></script>
     <script src="../_static/clipboard.min.js?v=a7894cd8"></script>
@@ -74,7 +74,7 @@
     <link rel="prev" title="Contract events" href="event.html" />
   <meta name="viewport" content="width=device-width, initial-scale=1"/>
   <meta name="docsearch:language" content="en"/>
-  <meta name="docsearch:version" content="master" />
+  <meta name="docsearch:version" content="8170-bruno-doc-jobs-streamline-build-deps" />
   </head>

(f624d00e replaced with fe51d915 and master replaced with 8170-bruno-doc-jobs-streamline-build-deps).

It also contains diff of binary files (.doctree, and .inv) - I'm not sure what it is.

############################################################
## DIFF for: docs/_build/.doctrees/developer/proposal_testing.doctree
############################################################
Binary files 12497863614/docs/_build/.doctrees/developer/proposal_testing.doctree and 12497192126/docs/_build/.doctrees/developer/proposal_testing.doctree differ


############################################################
## DIFF for: docs/_build/objects.inv
############################################################
Binary files 12497863614/docs/_build/objects.inv and 12497192126/docs/_build/objects.inv differ

Next steps

• Merge documentation.manuals into documentation.build_all (branch 8170-bruno-merge-doc-manuals).

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR