ci: Fix generation of list of packages to update

Workflow bump.yml performs a dry run of the "cargo upgrade" command, and
processes its output to determine the list of packages to upgrade (then
upgrades them as individual commits). It expects the output to be a
Markdown array, of this kind:

    name     old req compatible latest new req
    ====     ======= ========== ====== =======
    netdev   0.34.0  0.34.1     0.34.1 0.34.1
    smallvec 1.14.0  1.15.0     1.15.0 1.15.0

However, the recent introduction of the dataplane CLI with a separate
binary, and in particular, a set of dependency crates that are not
managed from the toplevel Cargo.toml, caused "cargo upgrade" to process
two files and to produce two different tables:

    $ cargo upgrade --incompatible=allow --dry-run 2>/dev/null
    name     old req compatible latest new req
    ====     ======= ========== ====== =======
    netdev   0.34.0  0.34.1     0.34.1 0.34.1
    smallvec 1.14.0  1.15.0     1.15.0 1.15.0
    name old req compatible latest new req
    ==== ======= ========== ====== =======
    log  ^0.4.25 0.4.27     0.4.27 ^0.4.27

This is obviously an issue for the workflow, that expects a single table
when parsing the output.

One solution is to move all dependencies for the CLI to the toplevel
crate. This is a separate discussion. In any case, we don't want the
workflow to break when processing multiple Cargo.toml. Fix the sed
expression to remove all heading and separator lines from the output (it
appears that we can collapse dependencies from all Cargo.toml into a
single list and treat the packages irrespective of the binary using them
when running "cargo upgrade"; version conflicts have not happened yet,
and are assumed to be solved by moving the dependency to the toplevel
Cargo.toml).

This is not expected to solve the issues currently observed with the
bump.yml workflow, but should improve resilience anyway.

Signed-off-by: Quentin Monnet <qmo@qmon.net>

Author: qmonnet

.github/workflows/bump.yml

@@ -110,9 +110,12 @@ jobs:
           # Check updates available with "cargo upgrade",
           # then bump each package individually through separate commits
           cargo upgrade --incompatible=allow --dry-run > upgrade_output.txt
-          sed '0,/^====/d; s/ .*//' upgrade_output.txt > list_packages.txt
+          sed '/^====/d; /^name .* new req$/d; s/ .*//' upgrade_output.txt > list_packages.txt
           nb_upgrades=$(wc -l < list_packages.txt)
 
+          echo "Found the following ${nb_upgrades} upgrade(s) available:"
+          cat list_packages.txt
+
           while read -r package; do
               echo "bump(cargo)!: bump $package (cargo upgrade)" | tee commit_msg.txt
               echo '' | tee -a commit_msg.txt