fbcode_builder: emit Show runner info step and timeout-minutes per generated job

Summary:
Adds two diagnostics to the GitHub Actions workflows generated by `getdeps.py generate-github-actions`:

1. **`Show runner info` step** as the first step in every job, dumping CPU core count, CPU model, and total RAM in OS-appropriate form: `nproc` / `/proc/cpuinfo` / `free -h` on Linux, `sysctl` on macOS, `Get-CimInstance` in pwsh on Windows. Surfaces the runner shape in CI logs so failures with thread-count or memory dependencies are easier to diagnose without manual workflow edits.

2. **`timeout-minutes`** on the build job. Defaults to 60 minutes (vs the 6-hour GitHub default), and can be overridden per-project via `timeout_minutes = N` in the `[github.actions]` section of the project manifest. The `timeout_minutes` field is added to the `[github.actions]` schema in `getdeps/manifest.py`.

Rebalancer's downstream OSS branch (richard/fixes) hand-edits both of these into its three generated workflow YAMLs to compensate for the gap. Centralizing them in the generator means rebalancer (and any other downstream that does the same) stops fighting regenerations. None of the 30 `generated` `getdeps_*.yml` files currently checked into fbsource have these additions, so this diff is a strict superset of the existing CI behavior — projects that don't want the diagnostics simply get them at no behavioral cost; projects that already wanted them no longer need to maintain hand-edits.

Reviewed By: sahilsd

Differential Revision: D101588403

fbshipit-source-id: f67a50755897e6809ea25a6940ca6679e9913c58

Author: r-barnes

build/fbcode_builder/getdeps.py

@@ -1091,6 +1091,9 @@ def write_job_for_platform(self, platform, args):  # noqa: C901
         override_build_type = args.build_type or manifest.get(
             "github.actions", "build_type", ctx=manifest_ctx
         )
+        timeout_minutes = (
+            manifest.get("github.actions", "timeout_minutes", ctx=manifest_ctx) or "60"
+        )
         if run_tests:
             manifest_ctx.set("test", "on")
         run_on = self.get_run_on(args)
@@ -1177,11 +1180,38 @@ def write_job_for_platform(self, platform, args):  # noqa: C901
 
             out.write("  build:\n")
             out.write("    runs-on: %s\n" % runs_on)
+            out.write(f"    timeout-minutes: {timeout_minutes}\n")
             if use_sccache:
                 out.write("    env:\n")
                 out.write('      SCCACHE_GHA_ENABLED: "on"\n')
             out.write("    steps:\n")
 
+            if build_opts.is_linux():
+                out.write("    - name: Show runner info\n")
+                out.write("      run: |\n")
+                out.write('        echo "CPU cores: $(nproc)"\n')
+                out.write("        cat /proc/cpuinfo | grep 'model name' | head -1\n")
+                out.write("        free -h\n")
+            elif build_opts.is_darwin():
+                out.write("    - name: Show runner info\n")
+                out.write("      run: |\n")
+                out.write('        echo "CPU cores: $(sysctl -n hw.ncpu)"\n')
+                out.write("        sysctl -n machdep.cpu.brand_string\n")
+                out.write(
+                    "        sysctl -n hw.memsize | "
+                    'awk \'{print "Memory: " $1/1073741824 " GB"}\'\n'
+                )
+            elif build_opts.is_windows():
+                out.write("    - name: Show runner info\n")
+                out.write("      run: |\n")
+                out.write('        echo "CPU cores: $env:NUMBER_OF_PROCESSORS"\n')
+                out.write("        (Get-CimInstance Win32_Processor).Name\n")
+                out.write(
+                    "        [math]::Round((Get-CimInstance Win32_ComputerSystem)"
+                    '.TotalPhysicalMemory / 1GB, 1).ToString() + " GB RAM"\n'
+                )
+                out.write("      shell: pwsh\n")
+
             if build_opts.is_windows():
                 # cmake relies on BOOST_ROOT but GH deliberately don't set it in order
                 # to avoid versioning issues:

build/fbcode_builder/getdeps/manifest.py

@@ -111,6 +111,7 @@
             "rust_version": OPTIONAL,
             "build_type": OPTIONAL,
             "sccache": OPTIONAL,
+            "timeout_minutes": OPTIONAL,
         },
     },
     "crate.pathmap": {"optional_section": True},