Remove written in clause

Recently we discussed in `rust-bitcoin` the pointlessness of the `\\
Written in ...` clause above the license terms. We came to the
conclusion that:

- It probably wasn't written then and who cares anyway because we patch
files all the time
- It almost certainly wasn't written by just this person because we have
a bunch of contributors
- Use of "the rust bitcoin devs" is just noise and no signal

Remove the "written in" clause if it contains "the rust bitcoin devs" or
Andrew's name (because he was part of the conversation in rust-bitcoin)

Do no remove clauses that have Sanket's name or Maxim's. Its up to them
if they want attribution so we leave it there for now.

Leave Andrew's name in `lib.rs` as a little nod-of-the-head to him as
the original author. I do not know the full relationship between Sanket
and Andrew and who did what so please forgive me Sanket if this is wrong.

Author: heap-coder

src/descriptor/bare.rs

@@ -1,4 +1,3 @@
-// Written in 2020 by the rust-miniscript developers
 // SPDX-License-Identifier: CC0-1.0
 
 //! # Bare Output Descriptors

src/descriptor/mod.rs

@@ -1,4 +1,3 @@
-// Written in 2018 by Andrew Poelstra <apoelstra@wpsoftware.net>
 // SPDX-License-Identifier: CC0-1.0
 
 //! # Output Descriptors

src/descriptor/segwitv0.rs

@@ -1,4 +1,3 @@
-// Written in 2020 by the rust-miniscript developers
 // SPDX-License-Identifier: CC0-1.0
 
 //! # Segwit Output Descriptors

src/descriptor/sh.rs

@@ -1,4 +1,3 @@
-// Written in 2020 by the rust-miniscript developers
 // SPDX-License-Identifier: CC0-1.0
 
 //! # P2SH Descriptors

src/descriptor/sortedmulti.rs

@@ -1,4 +1,3 @@
-// Written in 2020 by the rust-miniscript developers
 // SPDX-License-Identifier: CC0-1.0
 
 //! # Sorted Multi

src/expression.rs

@@ -1,4 +1,3 @@
-// Written in 2019 by Andrew Poelstra <apoelstra@wpsoftware.net>
 // SPDX-License-Identifier: CC0-1.0
 
 //! # Function-like Expression Language

src/iter/mod.rs

@@ -1,4 +1,3 @@
-// Written in 2023 by Andrew Poelstra <apoelstra@wpsoftware.net>
 // SPDX-License-Identifier: CC0-1.0
 
 //! Abstract Tree Iteration

src/iter/tree.rs

@@ -1,4 +1,3 @@
-// Written in 2023 by Andrew Poelstra <apoelstra@wpsoftware.net>
 // SPDX-License-Identifier: CC0-1.0
 
 //! Abstract Trees

src/miniscript/analyzable.rs

@@ -1,4 +1,3 @@
-// Written in 2018 by Andrew Poelstra <apoelstra@wpsoftware.net>
 // SPDX-License-Identifier: CC0-1.0
 
 //!  Miniscript Analysis

src/miniscript/astelem.rs

@@ -1,4 +1,3 @@
-// Written in 2019 by Andrew Poelstra <apoelstra@wpsoftware.net>
 // SPDX-License-Identifier: CC0-1.0
 
 //! AST Elements