chore: replace modified Apache-2.0 text with the official license

The LICENSE was a near-copy of Apache-2.0: section 9's heading read
"Accepting Warranty or Additional Support" instead of "Additional
Liability", and the appendix placeholder had been filled in with an
unrelated personal name. A license that isn't reproduced verbatim isn't
the license it claims to be, and GitHub's fuzzy detection still reported
Apache-2.0, hiding the defect.

Replace it with the verbatim text from apache.org, byte-identical to the
LICENSE in neondatabase/neon, neonctl, and toolkit.

LICENSE

@@ -1,3 +1,4 @@
+
                                  Apache License
                            Version 2.0, January 2004
                         http://www.apache.org/licenses/
@@ -162,7 +163,7 @@
       other commercial damages or losses), even if such Contributor
       has been advised of the possibility of such damages.
 
-   9. Accepting Warranty or Additional Support. While redistributing
+   9. Accepting Warranty or Additional Liability. While redistributing
       the Work or Derivative Works thereof, You may choose to offer,
       and charge a fee for, acceptance of support, warranty, indemnity,
       or other liability obligations and/or rights consistent with this
@@ -186,7 +187,7 @@
       same "printed page" as the copyright notice for easier
       identification within third-party archives.
 
-   Copyright 2025 Andre Landgraf
+   Copyright [yyyy] [name of copyright owner]
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
@@ -198,4 +199,4 @@
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
-   limitations under the License.
+   limitations under the License.