gh-40888: replace gone in python3.14 FancyURL
    
FancyURL has been long deprecated, since Python 3.3.
It's finally gone in 3.14, so we need this to move forward, e.g. on
Fedora 43,
as reported on [sage-support](https://groups.google.com/g/sage-
support/c/12GaUYfAbD0/m/1RcOQypjAwAJ)

This will fix #40886

### 📝 Checklist

<!-- Put an `x` in all the boxes that apply. -->

- [x] The title is concise and informative.
- [x] The description explains in detail what this PR is about.
- [x] I have linked a relevant issue or discussion.
- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation and checked the documentation
preview.

### ⌛ Dependencies

<!-- List all open PRs that this PR logically depends on. For example,
-->
<!-- - #12345: short description why this is a dependency -->
<!-- - #34567: ... -->
    
URL: #40888
Reported by: Dima Pasechnik
Reviewer(s): Enrique Manuel Artal Bartolo

Author: Release Manager

build/sage_bootstrap/download/transfer.py

@@ -20,7 +20,8 @@
 log = logging.getLogger()
 
 from sage_bootstrap.stdio import flush
-from sage_bootstrap.compat import urllib
+import urllib
+from urllib.request import build_opener, install_opener, urlretrieve
 
 
 class ProgressBar(object):
@@ -120,16 +121,17 @@ def error_progress_bar(self):
             self.progress_bar.error_stop()
 
     def run(self):
-        opener = urllib.FancyURLopener()
+        opener = build_opener()
+        install_opener(opener)
+
         opener.http_error_default = self.http_error_default
         self.start_progress_bar()
         try:
             if self.progress:
-                filename, info = opener.retrieve(
-                    self.url, self.destination, self.progress_bar)
+                urlretrieve(self.url, self.destination, reporthook=self.progress_bar)
             else:
-                filename, info = opener.retrieve(
-                    self.url, self.destination)
+                urlretrieve(self.url, self.destination)
+
         except IOError as error:
             self.error_progress_bar()
             log.error(error)

build/sage_bootstrap/uncompress/tar_file.py

@@ -20,6 +20,7 @@
 import stat
 import subprocess
 import time
+import inspect
 
 from io import BytesIO
 
@@ -96,9 +97,10 @@ def extractall(self, path='.', members=None, **kwargs):
             members = [m if isinstance(m, tarfile.TarInfo)
                        else name_to_member[m]
                        for m in members]
-        return super(SageBaseTarFile, self).extractall(path=path,
-                                                       members=members,
-                                                       **kwargs)
+        tfile = super(SageBaseTarFile, self)
+        if 'filter' in inspect.signature(tfile.extractall).parameters:
+            kwargs['filter'] = 'fully_trusted'
+        return tfile.extractall(path=path, members=members, **kwargs)
 
     def extractbytes(self, member):
         """