rust: document bindgen 0.71.0 regression

`bindgen` 0.71.0 regressed [1] on the "`--version` requires header"
issue which appeared in 0.69.0 first [2] and was fixed in 0.69.1. It
has been fixed again in 0.71.1 [3].

Thus document it so that, when we upgrade the minimum past 0.69.0 in the
future, we do not forget that we cannot remove the workaround until we
arrive at 0.71.1 at least.

Link: rust-lang/rust-bindgen#3039 [1]
Link: rust-lang/rust-bindgen#2677 [2]
Link: https://github.com/rust-lang/rust-bindgen/blob/main/CHANGELOG.md#v0711-2024-12-09 [3]
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20241209212544.1977065-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Author: ojeda

init/Kconfig

@@ -1989,8 +1989,10 @@ config BINDGEN_VERSION_TEXT
 	string
 	depends on RUST
 	# The dummy parameter `workaround-for-0.69.0` is required to support 0.69.0
-	# (https://github.com/rust-lang/rust-bindgen/pull/2678). It can be removed when
-	# the minimum version is upgraded past that (0.69.1 already fixed the issue).
+	# (https://github.com/rust-lang/rust-bindgen/pull/2678) and 0.71.0
+	# (https://github.com/rust-lang/rust-bindgen/pull/3040). It can be removed
+	# when the minimum version is upgraded past the latter (0.69.1 and 0.71.1
+	# both fixed the issue).
 	default "$(shell,$(BINDGEN) --version workaround-for-0.69.0 2>/dev/null)"
 
 #

scripts/rust_is_available.sh

@@ -123,8 +123,10 @@ fi
 # Non-stable and distributions' versions may have a version suffix, e.g. `-dev`.
 #
 # The dummy parameter `workaround-for-0.69.0` is required to support 0.69.0
-# (https://github.com/rust-lang/rust-bindgen/pull/2678). It can be removed when
-# the minimum version is upgraded past that (0.69.1 already fixed the issue).
+# (https://github.com/rust-lang/rust-bindgen/pull/2678) and 0.71.0
+# (https://github.com/rust-lang/rust-bindgen/pull/3040). It can be removed when
+# the minimum version is upgraded past the latter (0.69.1 and 0.71.1 both fixed
+# the issue).
 rust_bindings_generator_output=$( \
 	LC_ALL=C "$BINDGEN" --version workaround-for-0.69.0 2>/dev/null
 ) || rust_bindings_generator_code=$?