feat: add helm profiling preset

[wehzzz]

What does this PR do?

Adds a new profiling preset to the opentelemetry-collector Helm chart. When presets.profiling.enabled: true, the chart automatically configures:

• A profiling receiver and a profiles pipeline with debug exporter as fallback if no exporter configured
• A tracefs host volume mount (/sys/kernel/tracing, read-only)
• hostPID: true on the pod spec
• Security context (runAsUser: 0, runAsGroup: 0, privileged: true)

When combined with the kubernetesAttributes preset, the chart also:

• Injects the k8sattributes processor into the profiles pipeline (same pattern as logs/metrics/traces)
• Adds container.id to the pod_association configuration - eBPF profilers identify workloads by container ID, not pod IP/UID.

Motivation

Deploying an eBPF profiler (e.g. opentelemetry-collector-ebpf-profiler) on Kubernetes currently requires significant boilerplate. This was discussed in open-telemetry/opentelemetry-ebpf-profiler#1072 where the community expressed interest in a preset to simplify this.

Describe how you validated your changes

Two new CI values files:

• ci/preset-profiling-values.yaml - profiling preset only
• ci/preset-profiling-kubernetesattributes-values.yaml - profiling + kubernetesAttribute

Additional notes

• The container.id pod_association injection is gated on $config.service.pipelines.profiles existence in applyKubernetesAttributesConfig, not on profiling.enabled. This means any profiles pipeline (preset or user-defined) benefits from the enrichment when kubernetesAttributes is enabled.

• hostPID is applied to all three workload templates (DaemonSet, Deployment, StatefulSet) for consistency.

[florianl]

Overall looks good to me - but I'm not an helm expert. Just a minor question around the set resource limits.

[florianl]

Was this memory limit tested in some way? Depending on the environment, my experiments usually require 400M to 500M.

[wehzzz]

If I'm not mistaken, this limit is only used for the CI environment. It's not a default value injected by kubernetesattributes or the new profiling preset.

[nicolastakashi]

What we expect if profiling.enabled: true and hostPID: ""?

[wehzzz]

Since the eBPF profiler requires hostPID: true to function, it makes sense that enabling the profiling preset forces this value to true, regardless of whether hostPID is left empty ("") in the user's configuration.