[chore] Clean up some UTF-8 encoded characters, fix links

[chalin]

• Context: [CI] Add a check and/or fix script for multi-character UTF-8 encoded characters that can cause problems #6450
• Inspired by the GH action failures of fix: update links to OpenTelemetry Operator API documentation #6448, namely the link-check issues reported by https://github.com/open-telemetry/opentelemetry.io/actions/runs/13605322132/job/38036110496
• Replaces UTF-8 encoded non-breaking spaces by regular spaces (I didn't see any use that justified using   instead of a regular space).
• Replaced UTF-8 encoded apostrophes in one file (the one touched by fix: update links to OpenTelemetry Operator API documentation #6448) by a "plain" '.