gh-124452: Fix header mismatches when folding/unfolding with email message #130503

Job	Run time
Change detection / Compute changed files	15s
Check if Autoconf files are up to date	21s
Check if generated files are up to date	3m 26s
Address sanitizer	7m 33s
Ubuntu SSL tests with OpenSSL (ubuntu-22.04, 3.0.15)	2m 0s
Ubuntu SSL tests with OpenSSL (ubuntu-22.04, 3.1.7)	1m 57s
Windows MSI${{ '' }}	0s
Ubuntu SSL tests with OpenSSL (ubuntu-22.04, 3.2.3)	2m 13s
Hypothesis tests on Ubuntu	5m 16s
Ubuntu SSL tests with OpenSSL (ubuntu-22.04, 3.3.2)	2m 7s
CIFuzz	0s
Thread sanitizer / Thread sanitizer	3m 0s
Thread sanitizer (free-threading) / Thread sanitizer	7m 25s
WASI / build and test	6m 46s
Windows / build (arm64)	3m 10s
Windows (free-threading) / build (arm64)	3m 27s
Windows / build and test (Win32)	16m 20s
Windows (free-threading) / build and test (Win32)	24m 32s
Windows / build and test (x64)	16m 2s
Windows (free-threading) / build and test (x64)	23m 8s
macOS (free-threading) / build and test (ghcr.io/cirruslabs/macos-runner:sonoma)	5m 41s
macOS / build and test (ghcr.io/cirruslabs/macos-runner:sonoma)	5m 58s
macOS / build and test (macos-13)	8m 31s
Ubuntu / build and test (ubuntu-22.04)	7m 22s
Ubuntu (free-threading) / build and test (ubuntu-22.04)	9m 33s
Docs / Docs	2m 12s
Docs / Docs (Oldest Sphinx)	2m 3s
Docs / Doctest	29m 25s
All required checks pass	4s
	3h 19m 47s

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