fix(bbg): harden install retry for raw.githubusercontent SSL flake

- retry/action.yml: set -uo pipefail (was set -u) so wget/curl|bash
  pipeline failures propagate (rc from wget, not bash) and outer
  5x retry actually triggers
- bbg/action.yml: switch wget github.com/raw redirect to direct
  raw.githubusercontent curl -fsSL --retry 5 --retry-all-errors
  --connect-timeout 30 + set -o pipefail; avoids 302 hop and gives
  5 inner retries x 5 outer retries for raw SSL flake seen in
  32777404961 (Unable to establish SSL connection -> exit 4)

.github/actions/bbg/action.yml

@@ -8,7 +8,8 @@ runs:
       uses: ./.github/actions/retry
       with:
         command: |
-          wget -O- https://github.com/vc-teahouse/Baseband-guard/raw/main/setup.sh | bash
+          set -o pipefail
+          curl -fsSL --retry 5 --retry-delay 5 --retry-all-errors --connect-timeout 30 https://raw.githubusercontent.com/vc-teahouse/Baseband-guard/main/setup.sh | bash
         attempts: 5
         delay: 5
         workdir: ${{ github.workspace }}/kernel

.github/actions/retry/action.yml

@@ -23,7 +23,7 @@ runs:
     - shell: bash
       working-directory: ${{ inputs.workdir }}
       run: |
-        set -u
+        set -uo pipefail
         attempts="${{ inputs.attempts }}"
         delay="${{ inputs.delay }}"