fix(obs): support custom OTLP CA bundles (#8060)

Add RUSTFS_OBS_TLS_CA_FILE for additive private CA trust in OTLP HTTP exporters.

Co-authored-by: zhi22915 <qiuzgang@gmail.com>

Cargo.lock

@@ -10408,6 +10408,8 @@ dependencies = [
  "opentelemetry_sdk",
  "percent-encoding",
  "pyroscope",
+ "rcgen",
+ "reqwest",
  "rustfs-audit",
  "rustfs-common",
  "rustfs-config",
@@ -10421,6 +10423,8 @@ dependencies = [
  "rustfs-storage-api",
  "rustfs-utils",
  "rustix",
+ "rustls",
+ "rustls-pki-types",
  "serde",
  "serde_json",
  "sysinfo",
@@ -10428,6 +10432,7 @@ dependencies = [
  "tempfile",
  "thiserror 2.0.20",
  "tokio",
+ "tokio-rustls",
  "tokio-util",
  "tracing",
  "tracing-appender",