fix(publish): make retry_publish surface failure output under bash -e

Both retry_publish functions captured command output via:

  output=$("$@" 2>&1)
  rc=$?
  echo "$output"

GitHub Actions launches bash with -e (errexit). Under set -e, a failing
command substitution can terminate the script before the next line runs.
That meant when vsce or ovsx returned non-zero, the script died at the
`output=$(...)` line — neither the captured output nor the retry/
classification logic ever executed. The job just exited with code 1
showing only the '##[group]vsce publish attempt 1/5' header.

The previous single-target version of this workflow had the same bug
latent; it never triggered because vsce always succeeded for that flow.
The new multi-target run hit a real vsce failure and the bug ate the
diagnostic.

Replace the bare assignment with an explicit if/else, which set -e is
documented to handle correctly:

  if output=$("$@" 2>&1); then rc=0; else rc=$?; fi
  echo "$output"

No version bump — 0.2.2 was never on the Marketplace (vsce publish
silently failed for all 4 targets), so the prepare gate will let a
re-run through. ovsx already has 0.2.2 for all targets and will return
'already exists' which retry_publish treats as idempotent success.

Author: AlemTuzlak

.github/workflows/publish.yml

@@ -239,8 +239,12 @@ jobs:
             local i output rc wait
             for (( i=1; i<=attempts; i++ )); do
               echo "::group::vsce publish attempt $i/$attempts (${{ matrix.target }})"
-              output=$("$@" 2>&1)
-              rc=$?
+              # The if/else is load-bearing: GitHub runs `bash -e`, and a
+              # failed command substitution `output=$(cmd)` under set -e
+              # terminates the script *before* the echo below can run, so
+              # vsce/ovsx errors get swallowed silently. The if-form is
+              # explicitly handled by set -e and lets both branches set rc.
+              if output=$("$@" 2>&1); then rc=0; else rc=$?; fi
               echo "$output"
               echo "::endgroup::"
 
@@ -302,8 +306,12 @@ jobs:
             local i output rc wait
             for (( i=1; i<=attempts; i++ )); do
               echo "::group::ovsx publish attempt $i/$attempts (${{ matrix.target }})"
-              output=$("$@" 2>&1)
-              rc=$?
+              # The if/else is load-bearing: GitHub runs `bash -e`, and a
+              # failed command substitution `output=$(cmd)` under set -e
+              # terminates the script *before* the echo below can run, so
+              # vsce/ovsx errors get swallowed silently. The if-form is
+              # explicitly handled by set -e and lets both branches set rc.
+              if output=$("$@" 2>&1); then rc=0; else rc=$?; fi
               echo "$output"
               echo "::endgroup::"