fix: update runc to 1.3.4 in Finch CI for symlink bind-mount support (aws#8655)

* fix: skip build-in-source symlink invoke tests on Finch runtime

Finch/containerd does not support bind-mounting over symlinks (fails with
'not a directory'). The Finch team confirmed this is a known bug on their side.

Instead of working around it in SAM CLI, skip the affected integration tests
when CONTAINER_RUNTIME=finch and remove the verification workflow.

Tests will be re-enabled once Finch ships the fix.

* fix: update runc to 1.3.4 for Finch symlink bind-mount support

Instead of skipping symlink integration tests on Finch, update runc
to 1.3.4 in the CI pipeline which fixes the underlying bind-mount
over symlink issue in containerd/runc.

- Install runc 1.3.4 after Finch package install, before service start
- Revert test skip decorator on TestInvokeBuildInSourceSymlinkedModules

Author: bnusunny

.github/workflows/integration-tests.yml

@@ -250,6 +250,15 @@ jobs:
           echo 'deb [signed-by=/usr/share/keyrings/runfinch-finch-archive-keyring.gpg arch=amd64] https://artifact.runfinch.com/deb noble main' | sudo tee /etc/apt/sources.list.d/runfinch-finch.list
           sudo apt update
           sudo apt install -y runfinch-finch
+          
+          # Update runc to 1.3.4 to fix symlink bind-mount issue
+          RUNC_VERSION="1.3.4"
+          echo "Updating runc to v${RUNC_VERSION}..."
+          wget -q "https://github.com/opencontainers/runc/releases/download/v${RUNC_VERSION}/runc.amd64" -O /tmp/runc
+          sudo install -m 755 /tmp/runc /usr/sbin/runc
+          sudo install -m 755 /tmp/runc /usr/bin/runc
+          echo "runc updated: $(runc --version)"
+          
           sudo systemctl enable --now finch
           sudo systemctl enable --now finch-buildkit
           sleep 3