fix(chapel-ci): preinstall libunwind-dev (Chapel .deb apt dependency)

Chapel 2.8.0 .deb apt-installs but fails with "Depends: libunwind-dev"
on stock ubuntu-22.04 runners — dpkg bails before unpacking. Install
libunwind-dev first across all 4 Chapel install sites.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: hyperpolymath

.github/workflows/chapel-ci.yml

@@ -65,6 +65,10 @@ jobs:
       - name: Install Chapel ${{ env.CHAPEL_VERSION }}
         run: |
           set -euo pipefail
+          # Chapel .deb's apt dep: libunwind-dev. Install first so dpkg
+          # doesn't bail out on unmet dependencies.
+          sudo apt-get update -qq
+          sudo apt-get install -y libunwind-dev
           curl -fsSL --retry 3 -o /tmp/chapel.deb "${{ env.CHAPEL_DEB_URL }}"
           sudo apt-get install -y /tmp/chapel.deb
           chpl --version
@@ -84,6 +88,10 @@ jobs:
       - name: Install Chapel ${{ env.CHAPEL_VERSION }}
         run: |
           set -euo pipefail
+          # Chapel .deb's apt dep: libunwind-dev. Install first so dpkg
+          # doesn't bail out on unmet dependencies.
+          sudo apt-get update -qq
+          sudo apt-get install -y libunwind-dev
           curl -fsSL --retry 3 -o /tmp/chapel.deb "${{ env.CHAPEL_DEB_URL }}"
           sudo apt-get install -y /tmp/chapel.deb
           chpl --version
@@ -111,6 +119,10 @@ jobs:
       - name: Install Chapel ${{ env.CHAPEL_VERSION }}
         run: |
           set -euo pipefail
+          # Chapel .deb's apt dep: libunwind-dev. Install first so dpkg
+          # doesn't bail out on unmet dependencies.
+          sudo apt-get update -qq
+          sudo apt-get install -y libunwind-dev
           curl -fsSL --retry 3 -o /tmp/chapel.deb "${{ env.CHAPEL_DEB_URL }}"
           sudo apt-get install -y /tmp/chapel.deb
       - name: Download Chapel artefacts
@@ -132,6 +144,10 @@ jobs:
       - name: Install Chapel ${{ env.CHAPEL_VERSION }}
         run: |
           set -euo pipefail
+          # Chapel .deb's apt dep: libunwind-dev. Install first so dpkg
+          # doesn't bail out on unmet dependencies.
+          sudo apt-get update -qq
+          sudo apt-get install -y libunwind-dev
           curl -fsSL --retry 3 -o /tmp/chapel.deb "${{ env.CHAPEL_DEB_URL }}"
           sudo apt-get install -y /tmp/chapel.deb
       - name: Download Chapel artefacts
@@ -191,6 +207,10 @@ jobs:
       - name: Install Chapel ${{ env.CHAPEL_VERSION }}
         run: |
           set -euo pipefail
+          # Chapel .deb's apt dep: libunwind-dev. Install first so dpkg
+          # doesn't bail out on unmet dependencies.
+          sudo apt-get update -qq
+          sudo apt-get install -y libunwind-dev
           curl -fsSL --retry 3 -o /tmp/chapel.deb "${{ env.CHAPEL_DEB_URL }}"
           sudo apt-get install -y /tmp/chapel.deb
       - name: Download Chapel artefacts