Remove double spaces from between test tags

I think these were introduced in the preceding commit due to trailing
spaces on end of lines before this PR. Python script for the update -
```
import os
import sys
from pathlib import Path

def usage():
    print("Usage " + sys.argv[0] + " [directory]")
    print("Processes all test tags within a [directory].")

def update_file(file_path) -> bool:
    with file_path.open("rt") as file:
        lines = file.readlines()
    if len(lines) == 0:
        print("File " + file_path + " is empty")
        return False
    if "  " not in lines[0]:
        return False
    lines[0] = lines[0].replace("  ", " ")
    with file_path.open("wt") as file:
        file.writelines(lines)
    return True

def main() -> int:
    if len(sys.argv) != 2:
        usage()
        return os.EX_USAGE
    directory = Path(sys.argv[1])
    if not directory.is_absolute():
        directory = Path(os.getcwd()) / directory
    print("Running against directory " + os.fspath(directory))
    if not directory.is_dir():
        print("Error - This is not a directory.")
        return os.EX_IOERR
    files = directory.glob("*/*.desc")
    tests_updated = 0
    for file_path in files:
        if not file_path.is_file():
            print(os.fspath(file_path) + " was expected to be a file "
                                         "but is not a file")
            continue
        if update_file(file_path):
            tests_updated += 1
    if tests_updated == 0:
        print("Error - No tests updated")
        return os.EX_NOTFOUND
    print(str(tests_updated) + " tests updated.")
    return os.EX_OK

if __name__ == '__main__':
    sys.exit(main())
```

Author: thomasspriggs

regression/cbmc/sat-solver-warning/test.desc

@@ -1,4 +1,4 @@
-CORE broken-z3-smt-backend broken-cprover-smt-backend  no-new-smt
+CORE broken-z3-smt-backend broken-cprover-smt-backend no-new-smt
 test.c
 --sat-solver lingeling
 ^EXIT=0$

regression/cbmc/sat-solver/test.desc

@@ -1,4 +1,4 @@
-CORE broken-z3-smt-backend broken-cprover-smt-backend  no-new-smt
+CORE broken-z3-smt-backend broken-cprover-smt-backend no-new-smt
 test.c
 --sat-solver cadical
 ^EXIT=10$

regression/cbmc/simplify_singleton_interval_7690/negative_test.desc

@@ -1,4 +1,4 @@
-CORE  no-new-smt
+CORE no-new-smt
 --trace
 singleton_interval_simp_neg.c
 ^VERIFICATION FAILED$

regression/cbmc/simplify_singleton_interval_7690/positive_test.desc

@@ -1,4 +1,4 @@
-CORE  no-new-smt
+CORE no-new-smt
 --trace
 singleton_interval_simp.c
 ^VERIFICATION FAILED$