[FIX] web: popover opened in rtl takes full space

before this commit: smiley box popover in rtl langauge takes full space it is
because of left:0 given on o_popover class by default, which will be converted
to right:0 when in rtl language and popover position will computed by popper
will set left:'some pixels' due to which it takes full space.

after this commit: smiley box will be displayed with expected width,
unnecessary will not be added, as we have removed left:0 css, hence it will not
be converted to right:0 when in RTL mode.

task-2418264

closes odoo/odoo#65419

X-original-commit: 0bd842ad62901499abb703c92b15496cdfa05cc0
Signed-off-by: Sébastien Theys (seb) <seb@odoo.com>

addons/web/static/src/scss/popover.scss

@@ -55,8 +55,6 @@
     max-width: 100vw;
 
     position: fixed;
-    top: 0; // will be updated in js
-    left: 0; // but let's set it in the viewport in case of test/debug
     z-index: 1060;
     border: 1px solid $border-color;
     background-color: #fff;