ci: record-if-missing when coming from stainless (#4408)

# What does this PR do?

we will typically need to record the missing json for net new APIs. use
record-if-missing so that the integration tests can re-record and commit
the files to the PR

set the stainless inference mode to record-if-missing, and properly pass
the pr_head_sha on workflow_call.

## Test Plan

see 2031824567
which uses this commit.

Signed-off-by: Charlie Doern <cdoern@redhat.com>

.github/workflows/integration-tests.yml

@@ -48,6 +48,10 @@ on:
         type: string
         default: 'default'
         description: 'Matrix configuration key from ci_matrix.json (e.g., "default", "stainless")'
+      pr_head_sha:
+        required: false
+        type: string
+        description: 'The SHA of the pull request head to checkout'
       test-all-client-versions:
         required: false
         type: boolean
@@ -67,6 +71,8 @@ jobs:
     steps:
       - name: Checkout repository
         uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
+        with:
+          ref: ${{ inputs.pr_head_sha || github.event.pull_request.head.sha || github.sha }}
 
       - name: Generate test matrix
         id: set-matrix
@@ -100,6 +106,8 @@ jobs:
     steps:
       - name: Checkout repository
         uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
+        with:
+          ref: ${{ inputs.pr_head_sha || github.event.pull_request.head.sha || github.sha }}
 
       - name: Setup test environment
         if: ${{ matrix.config.allowed_clients == null || contains(matrix.config.allowed_clients, matrix.client) }}
@@ -110,7 +118,7 @@ jobs:
           sdk_install_url: ${{ inputs.sdk_install_url || '' }}
           setup: ${{ matrix.config.setup }}
           suite: ${{ matrix.config.suite }}
-          inference-mode: 'replay'
+          inference-mode: ${{ matrix.config.inference_mode || 'replay' }}
 
       - name: Setup Node.js for TypeScript client tests
         if: ${{ matrix.client == 'server' }}
@@ -140,5 +148,5 @@ jobs:
                 || (matrix.client == 'server' && 'server:ci-tests')
                 || 'docker:ci-tests' }}
           setup: ${{ matrix.config.setup }}
-          inference-mode: 'replay'
+          inference-mode: ${{ matrix.config.inference_mode || 'replay' }}
           suite: ${{ matrix.config.suite }}

.github/workflows/stainless-builds.yml

@@ -181,6 +181,7 @@ jobs:
       sdk_install_url: ${{ inputs.sdk_install_url || needs.preview.outputs.sdk_install_url }}
       matrix_key: 'stainless'
       test-all-client-versions: false
+      pr_head_sha: ${{ needs.compute-branch.outputs.pr_head_sha }}
 
   merge:
     needs: compute-branch