testsuite: archiver: increase hashing test bytes

A lower value results in the hash running too fast and the time being rounded down to 0.0, resulting in the test failing.

src/borg/testsuite/archiver/create_cmd.py

@@ -786,7 +786,7 @@ class ArchiverTestCase(ArchiverTestCaseBase):
 
         # Test case set up: create a repository and a file
         self.cmd(f"--repo={self.repository_location}", "rcreate", "--encryption=none")
-        self.create_regular_file("testfile", contents=randbytes(15000000))  # more data might be needed for faster CPUs
+        self.create_regular_file("testfile", contents=randbytes(50000000))
         # Archive
         result = self.cmd(f"--repo={self.repository_location}", "create", "--stats", "test_archive", self.input_path)
         hashing_time = extract_hashing_time(result)
@@ -804,7 +804,7 @@ class ArchiverTestCase(ArchiverTestCaseBase):
 
         # Test case set up: create a repository and a file
         self.cmd(f"--repo={self.repository_location}", "rcreate", RK_ENCRYPTION)
-        self.create_regular_file("testfile", contents=randbytes(10000000))
+        self.create_regular_file("testfile", contents=randbytes(50000000))
         # Archive
         result = self.cmd(f"--repo={self.repository_location}", "create", "--stats", "test_archive", self.input_path)
         chunking_time = extract_chunking_time(result)