CH07: drop description of op_return limits

I think this is an overabundance of detail (and I'm not sure it's
correct about a 40-byte release; I think that may have been changed in
the RC phase).

There has also been recent (March 2023) discussion about making this
limit arbitrarily high, so this is something that might become outdated
quickly.

chapters/authorization-authentication.adoc

@@ -742,8 +742,8 @@ RETURN <data>
 ----
 
 ((("Proof of Existence")))((("DOCPROOF prefix")))The data portion is
-limited to 80 bytes and most often represents a hash, such as the output
-from the SHA256 algorithm (32 bytes). Many applications put a prefix in
+often represents a hash, such as the output
+from the SHA256 algorithm (32 bytes). Some applications put a prefix in
 front of the data to help identify the application. For example, the
 http://proofofexistence.com[Proof of Existence] digital notarization
 service uses the 8-byte prefix +DOCPROOF+, which is ASCII encoded as +44
@@ -763,27 +763,6 @@ script to "RETURN" with a +FALSE+ and halt. Thus, if you accidentally
 reference a +RETURN+ output as an input in a transaction, that
 transaction is invalid.
 
-A standard transaction (one that conforms to the +IsStandard()+ checks)
-can have only one +RETURN+ output. However, a single +RETURN+ output can
-be combined in a transaction with outputs of any other type.
-
-Two new command-line options have been added in Bitcoin Core as of
-version 0.10. The option +datacarrier+ controls relay and mining of
-+RETURN+ transactions, with the default set to "1" to allow them. The
-option +datacarriersize+ takes a numeric argument specifying the maximum
-size in bytes of the +RETURN+ script, 83 bytes by default, which, allows
-for a maximum of 80 bytes of +RETURN+ data plus one byte of +RETURN+
-opcode and two bytes of +PUSHDATA+ opcode.
-
-[NOTE]
-====
-+RETURN+ was initially proposed with a limit of 80 bytes, but the limit
-was reduced to 40 bytes when the feature was released. In February 2015,
-in version 0.10 of Bitcoin Core, the limit was raised back to 80 bytes.
-Nodes may choose not to relay or mine +RETURN+, or only relay and mine
-+RETURN+ containing less than 80 bytes of data.
-====
-
 [[locktime_limitations]]
 ===== Transaction locktime limitations